Systems & Control – Mechanisms — Paper 4 · IGCSE Design and Technology 0445

3 Explain, using an example, what is meant by ‘mechanical advantage’. … … … … [3]

3 marks

Mark scheme: 3 Clear explanation using relevant example – gear, levers, pulleys [1] Understanding of output force being greater than input force [1] normally being stated as a ratio [1] 3 2 marks, allow 2 marks for one well explained point

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4 (a) State one reason for using bearings in a machine. … [1] (b) Bearings will normally require lubrication. Describe the type of lubrication most suitable for the following purposes. Plain bearings in a car engine … Ball bearings in a cycle wheel … [2] (c) Nylon is often used as a material for plain bearings. Give two properties required of nylon when it is used as a bearing material. 1 … 2 … [2]

5 marks

Mark scheme: 4(a) Reasons will include reducing friction, reducing wear To provide support, prevent axial and radial movement To reduce energy usage in a mechanism 1 radial movement 4(b) Lubrication for a car crankshaft will be oil Lubrication for ball bearings will be grease 2 4(c) Properties of nylon will include: • It does not require any additional lubrication • Low coefficient of friction • Can be injection moulded into different shapes • Does not corrode / is resistant to chemicals / hard wearing • Lower cost than other materials 2 × 1 marks, 1 for each valid property 2 Allow ‘wears away more easily than shaft’

This question in 0445/42 May/June 2017

9 (a) Fig. 8 shows a cycle brake lever in the released and pulled position and the brake mechanism. outer cable inner cable brake mechanism brake lever in pulled position Fig. 8 (i) State the order of lever used on the brake lever. … [1] (ii) The brake lever and brake mechanism are connected by a cable. Give two benefits of a cable linkage. 1 … … 2 … … [2] (iii) Give one drawback of a cable linkage. … … [1] (iv) Fig. 9 shows the dimensions of the brake lever and part of the mechanism. 5N 35 cable 110 90 brake block 30 Fig. 9 Calculate the force generated at the brake block by a 5N pulling force at the end of the brake lever. … … … … … [4] (b) Mechanisms require energy to operate; it is often necessary to store the energy before it is used in a mechanism. (i) Use the words below to complete the sentence about the energy conversion that takes place when a battery is used to power a mechanism. light chemical mechanical heat electrical magnetic An electrical battery will convert stored … energy into … energy which is converted by a motor into … energy. [3] (ii) Give two examples of how energy, other than electrical energy, can be stored before it is used in a mechanism. 1 … 2 … [2] (iii) Explain, using an example, how designers can reduce the energy demand of a mechanism. … … … … [3] (c) (i) A ratchet and pawl mechanism will only rotate in one direction. Use sketches and notes to show how a ratchet and pawl mechanism works. [3] (ii) Name one other mechanism that will only rotate in one direction. … [1] (d) (i) Part of the cylinder head of an engine is shown in Fig. 10. rocker shaft rocker valve stem valve spring push rod cylinder head cam follower valve camshaft Fig. 10 The valve opens when the camshaft rotates and lifts the cam follower. Movement is transmitted through the push rod and rocker to the valve stem, opening the valve. The valve spring holds the valve closed until the cam lifts the push rod. Give two ways that a designer could change the distance moved by the valve as it opens. 1 … … 2 … … [2] (ii) State the movement of the rocker as the camshaft rotates. … [1] (e) Fig. 11 shows two screw threads with the same outside diameter. A B Fig. 11 (i) State one difference between the screw threads. … [1] (ii) Give one effect that will be noticed when using thread B compared to thread A. … … [1]

25 marks

Mark scheme: 9(a)(i) Second order / second class lever 1 9(a)(ii) Benefits of a cable could include: • Able to bend / be routed around tubes • High tensile strength • Easily replaced / adjusted • Low cost to replace • Can work over a long distance • Lighter than solid linkage 2 × 1 marks for valid benefits 2 Allow any other valid benefits Allow ‘ instant movement’ 9(a)(iii) Drawback could include: • Cables can stretch • Cables can corrode • Single wire in the cable can break causing friction in the casing 1 mark for valid drawback 1 Allow – cable can break Allow ‘maintenance needed’, cannot transmit compressive force’ 9(a)(iv) Increased force at brake lever 90 × 5 = 35 × load [1] Load = 12.86 N [1] Force at mechanism 110 × 12.857 = 30 × load [1] Final load = 47.14 N[1] 4 Allow ecf from first part of calculation Allow 47 N 4 for correct answer with no working Question Answer Marks Guidance 9(b)(i) An electrical battery will convert stored chemical energy into electrical energy which is converted by a motor into mechanical energy 3 × 1 marks 3 9(b)(ii) Storage systems include: • air receiver tank (pneumatics) • spring • raised weight • stored water (hydroelectric / tidal) • diverted water (water mill) • flywheel 2 × 1 marks 2 Allow other valid examples of stored energy Allow ‘GPE’ and ‘EPE’ Allow ‘steam in boiler’ 9(b)(iii) Examples could include engine design, car, aircraft, boat, white goods, washing machine, tumble dryer, fridge, freezer Factors in reducing energy demand could include: Reduced weight, improved aerodynamics, more rigid materials, and better insulation, reduction of friction, switch mechanism off, use alternative energy source 1 mark for suitable example, 2 marks for explanation with two valid points or one point explained in detail 3 9(c)(i) Ratchet drawing / notes [1] Pawl drawing / notes [1] spring or gravity drop for pawl [1] 3 9(c)(ii) One way mechanism is snail cam [1] 1 Allow worm and wheel 9(d)(i) Greater lift on the cam [1] Change fulcrum position on the rocker – reduce distance from rocker shaft to push rod [1] 2 9(d)(ii) The rocker movement is oscillation 1 Question Answer Marks Guidance 9(e)(i) The difference in the threads could be pitch or thread profile [1] 1 Allow mark for understanding shown 9(e)(ii) The effect when using thread B would be that it must be turned more times to provide the same linear movement as thread A It can also be tightened more effectively and will not work loose as easily 1 mark for valid effect 1 Allow – easier to turn Total: 25

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3 Explain, using an example, what is meant by ‘mechanical advantage’. … … … … [3]

3 marks

Mark scheme: 3 Clear explanation using relevant example – gear, levers, pulleys [1] Understanding of output force being greater than input force [1] normally being stated as a ratio [1] 3 2 marks, allow 2 marks for one well explained point

This question in 0445/43 May/June 2017

4 (a) State one reason for using bearings in a machine. … [1] (b) Bearings will normally require lubrication. Describe the type of lubrication most suitable for the following purposes. Plain bearings in a car engine … Ball bearings in a cycle wheel … [2] (c) Nylon is often used as a material for plain bearings. Give two properties required of nylon when it is used as a bearing material. 1 … 2 … [2]

5 marks

Mark scheme: 4(a) Reasons will include reducing friction, reducing wear To provide support, prevent axial and radial movement To reduce energy usage in a mechanism 1 radial movement 4(b) Lubrication for a car crankshaft will be oil Lubrication for ball bearings will be grease 2 4(c) Properties of nylon will include: • It does not require any additional lubrication • Low coefficient of friction • Can be injection moulded into different shapes • Does not corrode / is resistant to chemicals / hard wearing • Lower cost than other materials 2 × 1 marks, 1 for each valid property 2 Allow ‘wears away more easily than shaft’

This question in 0445/43 May/June 2017

9 (a) Fig. 8 shows a cycle brake lever in the released and pulled position and the brake mechanism. outer cable inner cable brake mechanism brake lever in pulled position Fig. 8 (i) State the order of lever used on the brake lever. … [1] (ii) The brake lever and brake mechanism are connected by a cable. Give two benefits of a cable linkage. 1 … … 2 … … [2] (iii) Give one drawback of a cable linkage. … … [1] (iv) Fig. 9 shows the dimensions of the brake lever and part of the mechanism. 5N 35 cable 110 90 brake block 30 Fig. 9 Calculate the force generated at the brake block by a 5N pulling force at the end of the brake lever. … … … … … [4] (b) Mechanisms require energy to operate; it is often necessary to store the energy before it is used in a mechanism. (i) Use the words below to complete the sentence about the energy conversion that takes place when a battery is used to power a mechanism. light chemical mechanical heat electrical magnetic An electrical battery will convert stored … energy into … energy which is converted by a motor into … energy. [3] (ii) Give two examples of how energy, other than electrical energy, can be stored before it is used in a mechanism. 1 … 2 … [2] (iii) Explain, using an example, how designers can reduce the energy demand of a mechanism. … … … … [3] (c) (i) A ratchet and pawl mechanism will only rotate in one direction. Use sketches and notes to show how a ratchet and pawl mechanism works. [3] (ii) Name one other mechanism that will only rotate in one direction. … [1] (d) (i) Part of the cylinder head of an engine is shown in Fig. 10. rocker shaft rocker valve stem valve spring push rod cylinder head cam follower valve camshaft Fig. 10 The valve opens when the camshaft rotates and lifts the cam follower. Movement is transmitted through the push rod and rocker to the valve stem, opening the valve. The valve spring holds the valve closed until the cam lifts the push rod. Give two ways that a designer could change the distance moved by the valve as it opens. 1 … … 2 … … [2] (ii) State the movement of the rocker as the camshaft rotates. … [1] (e) Fig. 11 shows two screw threads with the same outside diameter. A B Fig. 11 (i) State one difference between the screw threads. … [1] (ii) Give one effect that will be noticed when using thread B compared to thread A. … … [1]

25 marks

Mark scheme: 9(a)(i) Second order / second class lever 1 9(a)(ii) Benefits of a cable could include: • Able to bend / be routed around tubes • High tensile strength • Easily replaced / adjusted • Low cost to replace • Can work over a long distance • Lighter than solid linkage 2 × 1 marks for valid benefits 2 Allow any other valid benefits Allow ‘ instant movement’ 9(a)(iii) Drawback could include: • Cables can stretch • Cables can corrode • Single wire in the cable can break causing friction in the casing 1 mark for valid drawback 1 Allow – cable can break Allow ‘maintenance needed’, cannot transmit compressive force’ 9(a)(iv) Increased force at brake lever 90 × 5 = 35 × load [1] Load = 12.86 N [1] Force at mechanism 110 × 12.857 = 30 × load [1] Final load = 47.14 N[1] 4 Allow ecf from first part of calculation Allow 47 N 4 for correct answer with no working Question Answer Marks Guidance 9(b)(i) An electrical battery will convert stored chemical energy into electrical energy which is converted by a motor into mechanical energy 3 × 1 marks 3 9(b)(ii) Storage systems include: • air receiver tank (pneumatics) • spring • raised weight • stored water (hydroelectric / tidal) • diverted water (water mill) • flywheel 2 × 1 marks 2 Allow other valid examples of stored energy Allow ‘GPE’ and ‘EPE’ Allow ‘steam in boiler’ 9(b)(iii) Examples could include engine design, car, aircraft, boat, white goods, washing machine, tumble dryer, fridge, freezer Factors in reducing energy demand could include: Reduced weight, improved aerodynamics, more rigid materials, and better insulation, reduction of friction, switch mechanism off, use alternative energy source 1 mark for suitable example, 2 marks for explanation with two valid points or one point explained in detail 3 9(c)(i) Ratchet drawing / notes [1] Pawl drawing / notes [1] spring or gravity drop for pawl [1] 3 9(c)(ii) One way mechanism is snail cam [1] 1 Allow worm and wheel 9(d)(i) Greater lift on the cam [1] Change fulcrum position on the rocker – reduce distance from rocker shaft to push rod [1] 2 9(d)(ii) The rocker movement is oscillation 1 Question Answer Marks Guidance 9(e)(i) The difference in the threads could be pitch or thread profile [1] 1 Allow mark for understanding shown 9(e)(ii) The effect when using thread B would be that it must be turned more times to provide the same linear movement as thread A It can also be tightened more effectively and will not work loose as easily 1 mark for valid effect 1 Allow – easier to turn Total: 25

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4 Fig. 3 shows an ice cream scoop that uses a moveable bar to release a ball of ice cream when the lever is pressed. The lever operates a gear linked to the moveable bar. lever compression moveable bar spring gear Fig. 3 (a) State the conversion of motion that takes place when the lever is pressed. … motion in the lever is converted to … motion in the moveable bar. [2] (b) State the order of lever used in the ice cream scoop. … [1] (c) Describe how the movement of the lever is transferred to the moveable bar. … … … [2]

5 marks

Mark scheme: 4(a) Oscillating to Oscillating movement, 1 mark for each term. 2 4(b) Second order or class 2 lever. 1 4(c) The gear [1] transmits motion by meshing with the holes in lever [1] 2 Allow marks for understanding shown.

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5 Draw an example of a third order lever and label the position of the fulcrum, load and effort. [4]

4 marks

Mark scheme: 5 Any suitable third order lever, e.g. tweezers [1]. Position of effort shown between load and fulcrum, 1 mark each for L E F correctly positioned, 3 × 1 mark 4

This question in 0445/41 Oct/Nov 2017

11 Power sources used to operate mechanisms usually have safety features that will prevent injury to a user. (a) Complete the table using a suitable safety device for each power source from the list given below. One has been done for you. PTM switch solenoid valve fuse residual current device (RCD) regulator Power Source Safety Device mains electricity natural gas low voltage electricity fuse compressed air [3] (b) Two types of drive system are shown in Fig. 10. 60 t driver 10 t 40 t belt drive geared drive Fig. 10 (i) Describe two outcomes of using the belt drive system shown in Fig. 10. 1 … 2 … [2] (ii) Draw on Fig. 10 to show the direction of rotation of the 10 t gear and the 40 t gear in the geared drive system. [2] (iii) Give two benefits of using a belt drive rather than a geared drive. 1 … 2 … [2] (iv) Explain why drive systems cannot be 100% efficient. … … … … [3] (c) Fig. 11 shows a hand drill. Fig. 11 (i) Name the type of gear used in the hand drill. … [1] (ii) Give two reasons for using this type of gear in the hand drill. 1 … 2 … [2] (iii) State the velocity ratio of the gears used in the hand drill. … [2] (iv) Calculate the speed of the chuck when the handle turns the 56 t gear at 60 rpm. … … … [2] (v) The shaft of the hand drill rotates in plain bearings. Give one drawback of using plain bearings. … [1] (vi) The end of the shaft rotates against a ball bearing. Explain why the ball bearing is needed in this position. … … … … [2] (d) Fig. 12 shows a pair of garden shears with a compound or double lever action. Fig. 12 Calculate the mechanical advantage of the shears if the grass is being cut at the tip of the blade. … … … … … [3]

25 marks

Mark scheme: 11(a) 3 1 mark for each correct. 11(b)(i) The driven pulley will turn anti-clockwise, 1 mark, The speed of the driven pulley will be slower than the driver, 1 mark. 2 11(b)(ii) 1 mark for each arrow correct, 2 × 1 marks. 2 Arrows may be in different positions on the drawing. 11(b)(iii) Benefits of a belt drive could include: • Pulley position is not so critical • Belt can slip to save damage if a shaft is jammed • Lower initial cost and replacement belt cost than gears • Can be quieter in operation than gears • No lubrication required. 2 × 1 marks for valid benefits 2 Allow other valid benefits [1] [1] Power Source Safety Device natural gas compressed air mains electricity low voltage electricity solenoid valve fuse residual current device RCD regulator Question Answer Marks Guidance 11(b)(iv) Explanation should include: • Frictional losses • Energy lost in generation of heat and sound • Poorly fitting parts • Materials that cause losses e.g. belts that stretch or slip on initial start-up. 3 × 1 marks for each point in explanation. 3 Clear explanation with at least two points included, one point being well explained[3] Explanation with up to three points mentioned but no links to consequence of the cause of energy loss , [2] Award two marks for one point well explained. Single point mentioned, [1] 11(c)(i) Bevel gear, 1 mark 1 11(c)(ii) Reasons will include: • It can change the direction of the drive through 90° • Positive drive with no chance of slipping • Suited to large difference in 1number of teeth on the two gears. 2 × 1 marks. 2 Allow other valid reasons e.g. increased speed of driven gear. 11(c)(iii) 12:56 or 6:28 or 3:14 or 1:4.67 Correct numbers 1 mark, correct way around, 1 mark. 2 11(c)(iv) Speed of chuck = (56 / 12) × 60, 1 mark = 280 rpm, 1 mark 2 2 marks for correct answer with no working. Question Answer Marks Guidance 11(c)(v) Problems with plain bearings include: • Shorter working life than other types of bearing • Replacement may not be possible • Not as precise a fit in many cases • Lubrication will be required; other types can be sealed for life. • More friction / heat is generated 1 mark for valid answer. 1 11(c)(vi) The ball bearing absorbs the thrust from the end of the shaft, [1] when the drill bit is pressed onto the work. [1] Friction at the end of the shaft is reduced [1]. 2 Explanation with two points included [2] Explanation with a single point included [1] Allow 2 marks for one point fully explained. 11(d) Mechanical advantage of the first lever is 800 / 75 = 10.66 Mechanical advantage of the second lever is 40 / 220 = 0.18 Combined advantage is 10.66 × 0.18 = 1.94 3 3 marks for correct answer with no working.

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4 Fig. 3 shows an ice cream scoop that uses a moveable bar to release a ball of ice cream when the lever is pressed. The lever operates a gear linked to the moveable bar. lever compression moveable bar spring gear Fig. 3 (a) State the conversion of motion that takes place when the lever is pressed. … motion in the lever is converted to … motion in the moveable bar. [2] (b) State the order of lever used in the ice cream scoop. … [1] (c) Describe how the movement of the lever is transferred to the moveable bar. … … … [2]

5 marks

Mark scheme: 4(a) Oscillating to Oscillating movement, 1 mark for each term. 2 4(b) Second order or class 2 lever. 1 4(c) The gear [1] transmits motion by meshing with the holes in lever [1] 2 Allow marks for understanding shown.

This question in 0445/42 Oct/Nov 2017

5 Draw an example of a third order lever and label the position of the fulcrum, load and effort. [4]

4 marks

Mark scheme: 5 Any suitable third order lever, e.g. tweezers [1]. Position of effort shown between load and fulcrum, 1 mark each for L E F correctly positioned, 3 × 1 mark 4

This question in 0445/42 Oct/Nov 2017

11 Power sources used to operate mechanisms usually have safety features that will prevent injury to a user. (a) Complete the table using a suitable safety device for each power source from the list given below. One has been done for you. PTM switch solenoid valve fuse residual current device (RCD) regulator Power Source Safety Device mains electricity natural gas low voltage electricity fuse compressed air [3] (b) Two types of drive system are shown in Fig. 10. 60 t driver 10 t 40 t belt drive geared drive Fig. 10 (i) Describe two outcomes of using the belt drive system shown in Fig. 10. 1 … 2 … [2] (ii) Draw on Fig. 10 to show the direction of rotation of the 10 t gear and the 40 t gear in the geared drive system. [2] (iii) Give two benefits of using a belt drive rather than a geared drive. 1 … 2 … [2] (iv) Explain why drive systems cannot be 100% efficient. … … … … [3] (c) Fig. 11 shows a hand drill. Fig. 11 (i) Name the type of gear used in the hand drill. … [1] (ii) Give two reasons for using this type of gear in the hand drill. 1 … 2 … [2] (iii) State the velocity ratio of the gears used in the hand drill. … [2] (iv) Calculate the speed of the chuck when the handle turns the 56 t gear at 60 rpm. … … … [2] (v) The shaft of the hand drill rotates in plain bearings. Give one drawback of using plain bearings. … [1] (vi) The end of the shaft rotates against a ball bearing. Explain why the ball bearing is needed in this position. … … … … [2] (d) Fig. 12 shows a pair of garden shears with a compound or double lever action. Fig. 12 Calculate the mechanical advantage of the shears if the grass is being cut at the tip of the blade. … … … … … [3]

25 marks

Mark scheme: 11(a) 3 1 mark for each correct. 11(b)(i) The driven pulley will turn anti-clockwise, 1 mark, The speed of the driven pulley will be slower than the driver, 1 mark. 2 11(b)(ii) 1 mark for each arrow correct, 2 × 1 marks. 2 Arrows may be in different positions on the drawing. 11(b)(iii) Benefits of a belt drive could include: • Pulley position is not so critical • Belt can slip to save damage if a shaft is jammed • Lower initial cost and replacement belt cost than gears • Can be quieter in operation than gears • No lubrication required. 2 × 1 marks for valid benefits 2 Allow other valid benefits [1] [1] Power Source Safety Device natural gas compressed air mains electricity low voltage electricity solenoid valve fuse residual current device RCD regulator Question Answer Marks Guidance 11(b)(iv) Explanation should include: • Frictional losses • Energy lost in generation of heat and sound • Poorly fitting parts • Materials that cause losses e.g. belts that stretch or slip on initial start-up. 3 × 1 marks for each point in explanation. 3 Clear explanation with at least two points included, one point being well explained[3] Explanation with up to three points mentioned but no links to consequence of the cause of energy loss , [2] Award two marks for one point well explained. Single point mentioned, [1] 11(c)(i) Bevel gear, 1 mark 1 11(c)(ii) Reasons will include: • It can change the direction of the drive through 90° • Positive drive with no chance of slipping • Suited to large difference in 1number of teeth on the two gears. 2 × 1 marks. 2 Allow other valid reasons e.g. increased speed of driven gear. 11(c)(iii) 12:56 or 6:28 or 3:14 or 1:4.67 Correct numbers 1 mark, correct way around, 1 mark. 2 11(c)(iv) Speed of chuck = (56 / 12) × 60, 1 mark = 280 rpm, 1 mark 2 2 marks for correct answer with no working. Question Answer Marks Guidance 11(c)(v) Problems with plain bearings include: • Shorter working life than other types of bearing • Replacement may not be possible • Not as precise a fit in many cases • Lubrication will be required; other types can be sealed for life. • More friction / heat is generated 1 mark for valid answer. 1 11(c)(vi) The ball bearing absorbs the thrust from the end of the shaft, [1] when the drill bit is pressed onto the work. [1] Friction at the end of the shaft is reduced [1]. 2 Explanation with two points included [2] Explanation with a single point included [1] Allow 2 marks for one point fully explained. 11(d) Mechanical advantage of the first lever is 800 / 75 = 10.66 Mechanical advantage of the second lever is 40 / 220 = 0.18 Combined advantage is 10.66 × 0.18 = 1.94 3 3 marks for correct answer with no working.

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1 Fig. 1 shows the rear derailleur gear on a cycle with a close up view of the gear cable. outer gear cable inner gear cable outer gear cable inner gear cable nylon lining Fig. 1 (a) Name the force that has been applied, when manufacturing the inner gear cable to keep the strands of cable in position. … [1] (b) The outer gear cable has a nylon lining. Give two benefits of using the nylon lining. 1 … 2 … [2] (c) Explain why small radius bends should be avoided in the gear cable when it is attached to the cycle. … … … [2]

5 marks

Mark scheme: 1(a) Torque or torsion 1 Allow twisting 1(b) Benefits of the nylon lining could include: • Reduce friction • Reduce the amount of lubrication required • Prevent water getting to inner cable • Prevent inner cable rubbing on outer 2 × 1 marks for suitable benefits 2 Allow any other valid benefit. E.g. lightweight, waterproof, flexible. 1(c) Small radius bends will restrict the cable and prevent efficient movement of the inner cable. Permanent distortion of the outer cable could result. Possibility of cable snapping. 2 Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned, 1 mark.

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3 Hydraulic systems are now used for many applications rather than a control cable. State the force created in a hydraulic system. … [1]

1 marks

Mark scheme: 3 Compression 1

This question in 0445/41 May/June 2018

4 Fig. 2 shows the speed control lever on a wood turning lathe. Slow Fast Fig. 2 (a) Complete three of the labels to show the position of effort, load and fulcrum on the lever when it is used to change the speed of the lathe. [3] (b) State the order of lever used. … [1]

4 marks

Mark scheme: 4(a) 3 4(b) Second order lever 1 Accept 2nd class lever Fast Slow L F E

This question in 0445/41 May/June 2018

5 Choose from the terms below to complete the table. bevel gear idler gear rack and pinion worm gear Requirement Method Transfer drive through 90° with no change in speed Provide a large reduction in speed in a small space Make driver and driven shafts rotate in the same direction [3]

3 marks

Mark scheme: 5 Requirement Method Transfer drive through 90° with no change in speed bevel gear Provide a large reduction in speed in a small space worm gear Make driver and driven shafts rotate in the same direction idler gear 3

This question in 0445/41 May/June 2018

6 Fig. 3 shows a piece of rod with a square thread cut into it. 3 6 2519 Fig. 3 State the pitch of the thread. … [1]

1 marks

Mark scheme: 6 Thread pitch is 6 mm 1

This question in 0445/41 May/June 2018

11 Fig. 11 shows views of the chain drive on a cycle. 10 sprockets jockey wheels chain 2 chainrings Fig. 11 (a) (i) Describe two functions of the jockey wheels in the chain drive. 1 … … 2 … … [2] (ii) Calculate the number of gear ratios that are available on the cycle. … … [2] (iii) Name the factor, in addition to the number of sprockets and chainrings that will determine how far the cycle will travel for each rotation of the chainring. … [1] (b) (i) Explain why a chain should be lubricated. … … … [2] (ii) State why grease is not suitable for lubricating a chain. … (c) Fig. 12 shows three different types of bearing that can be used in a jockey wheel. rubber seal grooves R S T plain bearing – ceramic plain bearing – steel sealed ball bearing Fig. 12 (i) Give one reason for using a rubber seal either side of the bearing in type R. … … [1] (ii) The outer bearing face in type R has four grooves cut into the surface; this is a common feature when using plain bearings. State the reason for the grooves. … … [1] (iii) Give one benefit for each of the bearing types used in S and T. Bearing S … … Bearing T … … [2] (d) Fig. 13 shows the blade guide for a small bandsaw used for cutting timber. By turning handle A the guide can be raised or lowered to allow different thicknesses of timber to be cut. handle A visible part of mechanism blade guide saw table blade Fig. 13 (i) Name the mechanism used to raise and lower the blade guide when handle A is turned. … [2] (ii) State the conversion of motion which takes place when handle A is turned and the blade guide moves. … to … [2] (iii) When the bandsaw is in use there are energy losses. Name two ways in which the energy from the motor can be lost when the machine is in use. 1 … … 2 … … [2] (iv) Describe how energy loss in a powered machine can be reduced. … … … [2] (v) The guide fence for the saw is held securely in place by a cam lever shown in Fig. 14. unlocked locked position position cam profile Fig. 14 Explain why cams are often used where frequent adjustment is necessary. … … … [2] (e) Fig. 15 shows a compound pulley system. effort load Fig. 15 (i) State the mechanical advantage of the pulley system. … [1] (ii) Calculate the pulling force necessary to raise a load of 1.5 kN. … … … [2]

25 marks

Mark scheme: 11(a)(i) To tension the chain or take up excess chain length, 1 mark To guide the chain onto different sprockets, 1 mark 2 11(a)(ii) 2 chainrings × 10 sprockets, 1 mark = 20 gear ratios, 1 mark 2 Award 2 marks for 20 11(a)(iii) The diameter of the wheel will affect the distance travelled. 1 11(b)(i) Reasons for lubricating a chain include: • Reduce friction between rollers / links • Reduce wear of the chain • Keep water away from moving parts • Increase efficiency of the mechanism. 2 Allow any other valid reason. Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned 1 mark. 11(b)(ii) Grease would be too thick to get through to the inner sections of rollers. 1 11(c)(i) The rubber seals will: • Keep oil in place in the bearing • Keep dust / grit / water away from the bearing surfaces 1 11(c)(ii) The grooves act as a reservoir for the oil. They also allow grit / abrasive material to collect without damaging the bearing surface. 1 Allow mark for reference to oiling. 11(c)(iii) Benefit of type S: 1 mark • Simple design • Low cost • Easily replaced Benefit of type T: 1 mark • Reduced friction • Will take both axial and radial load • No maintenance required 2 Allow any other valid benefits. Do not allow the same benefit for both bearings. For T allow, ‘withstand force’. 11(d)(i) Rack and pinion, 1 mark for each 2 11(d)(ii) Rotary motion to linear motion, 1 mark for each 2 Allow ‘circular’ for ‘rotary’ Question Answer Marks Guidance 11(d)(iii) Energy losses can be through friction in bearings, sound, heat. 2 × 1 marks 2 11(d)(iv) Energy loss can be reduced by: • Use of efficient bearings to reduce friction • Lubrication • Reducing weight of any moving parts • Switching machine off when not in use. 2 Allow any other valid method of reducing energy loss. 11(d)(v) Factors will include: • Cams allow for quick adjustment • Limited movement needed • Positive locking action is possible • No tools required 2 Allow any other valid reason. Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned 1 mark. 11(e)(i) Mechanical advantage of the compound pulley is 8/1 = 8 1 11(e)(ii) 1.5 kN = 1500N / 8 [1] = 187.5 N, [1] 0.1875 kN 2

This question in 0445/41 May/June 2018

1 Fig. 1 shows the rear derailleur gear on a cycle with a close up view of the gear cable. outer gear cable inner gear cable outer gear cable inner gear cable nylon lining Fig. 1 (a) Name the force that has been applied, when manufacturing the inner gear cable to keep the strands of cable in position. … [1] (b) The outer gear cable has a nylon lining. Give two benefits of using the nylon lining. 1 … 2 … [2] (c) Explain why small radius bends should be avoided in the gear cable when it is attached to the cycle. … … … [2]

5 marks

Mark scheme: 1(a) Torque or torsion 1 Allow twisting 1(b) Benefits of the nylon lining could include: • Reduce friction • Reduce the amount of lubrication required • Prevent water getting to inner cable • Prevent inner cable rubbing on outer 2 × 1 marks for suitable benefits 2 Allow any other valid benefit. E.g. lightweight, waterproof, flexible. 1(c) Small radius bends will restrict the cable and prevent efficient movement of the inner cable. Permanent distortion of the outer cable could result. Possibility of cable snapping. 2 Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned, 1 mark.

This question in 0445/42 May/June 2018

3 Hydraulic systems are now used for many applications rather than a control cable. State the force created in a hydraulic system. … [1]

1 marks

Mark scheme: 3 Compression 1

This question in 0445/42 May/June 2018

4 Fig. 2 shows the speed control lever on a wood turning lathe. Slow Fast Fig. 2 (a) Complete three of the labels to show the position of effort, load and fulcrum on the lever when it is used to change the speed of the lathe. [3] (b) State the order of lever used. … [1]

4 marks

Mark scheme: 4(a) 3 4(b) Second order lever 1 Accept 2nd class lever Fast Slow L F E

This question in 0445/42 May/June 2018

5 Choose from the terms below to complete the table. bevel gear idler gear rack and pinion worm gear Requirement Method Transfer drive through 90° with no change in speed Provide a large reduction in speed in a small space Make driver and driven shafts rotate in the same direction [3]

3 marks

Mark scheme: 5 Requirement Method Transfer drive through 90° with no change in speed bevel gear Provide a large reduction in speed in a small space worm gear Make driver and driven shafts rotate in the same direction idler gear 3

This question in 0445/42 May/June 2018

6 Fig. 3 shows a piece of rod with a square thread cut into it. 3 6 2519 Fig. 3 State the pitch of the thread. … [1]

1 marks

Mark scheme: 6 Thread pitch is 6 mm 1

This question in 0445/42 May/June 2018

11 Fig. 11 shows views of the chain drive on a cycle. 10 sprockets jockey wheels chain 2 chainrings Fig. 11 (a) (i) Describe two functions of the jockey wheels in the chain drive. 1 … … 2 … … [2] (ii) Calculate the number of gear ratios that are available on the cycle. … … [2] (iii) Name the factor, in addition to the number of sprockets and chainrings that will determine how far the cycle will travel for each rotation of the chainring. … [1] (b) (i) Explain why a chain should be lubricated. … … … [2] (ii) State why grease is not suitable for lubricating a chain. … (c) Fig. 12 shows three different types of bearing that can be used in a jockey wheel. rubber seal grooves R S T plain bearing – ceramic plain bearing – steel sealed ball bearing Fig. 12 (i) Give one reason for using a rubber seal either side of the bearing in type R. … … [1] (ii) The outer bearing face in type R has four grooves cut into the surface; this is a common feature when using plain bearings. State the reason for the grooves. … … [1] (iii) Give one benefit for each of the bearing types used in S and T. Bearing S … … Bearing T … … [2] (d) Fig. 13 shows the blade guide for a small bandsaw used for cutting timber. By turning handle A the guide can be raised or lowered to allow different thicknesses of timber to be cut. handle A visible part of mechanism blade guide saw table blade Fig. 13 (i) Name the mechanism used to raise and lower the blade guide when handle A is turned. … [2] (ii) State the conversion of motion which takes place when handle A is turned and the blade guide moves. … to … [2] (iii) When the bandsaw is in use there are energy losses. Name two ways in which the energy from the motor can be lost when the machine is in use. 1 … … 2 … … [2] (iv) Describe how energy loss in a powered machine can be reduced. … … … [2] (v) The guide fence for the saw is held securely in place by a cam lever shown in Fig. 14. unlocked locked position position cam profile Fig. 14 Explain why cams are often used where frequent adjustment is necessary. … … … [2] (e) Fig. 15 shows a compound pulley system. effort load Fig. 15 (i) State the mechanical advantage of the pulley system. … [1] (ii) Calculate the pulling force necessary to raise a load of 1.5 kN. … … … [2]

25 marks

Mark scheme: 11(a)(i) To tension the chain or take up excess chain length, 1 mark To guide the chain onto different sprockets, 1 mark 2 11(a)(ii) 2 chainrings × 10 sprockets, 1 mark = 20 gear ratios, 1 mark 2 Award 2 marks for 20 11(a)(iii) The diameter of the wheel will affect the distance travelled. 1 11(b)(i) Reasons for lubricating a chain include: • Reduce friction between rollers / links • Reduce wear of the chain • Keep water away from moving parts • Increase efficiency of the mechanism. 2 Allow any other valid reason. Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned 1 mark. 11(b)(ii) Grease would be too thick to get through to the inner sections of rollers. 1 11(c)(i) The rubber seals will: • Keep oil in place in the bearing • Keep dust / grit / water away from the bearing surfaces 1 11(c)(ii) The grooves act as a reservoir for the oil. They also allow grit / abrasive material to collect without damaging the bearing surface. 1 Allow mark for reference to oiling. 11(c)(iii) Benefit of type S: 1 mark • Simple design • Low cost • Easily replaced Benefit of type T: 1 mark • Reduced friction • Will take both axial and radial load • No maintenance required 2 Allow any other valid benefits. Do not allow the same benefit for both bearings. For T allow, ‘withstand force’. 11(d)(i) Rack and pinion, 1 mark for each 2 11(d)(ii) Rotary motion to linear motion, 1 mark for each 2 Allow ‘circular’ for ‘rotary’ Question Answer Marks Guidance 11(d)(iii) Energy losses can be through friction in bearings, sound, heat. 2 × 1 marks 2 11(d)(iv) Energy loss can be reduced by: • Use of efficient bearings to reduce friction • Lubrication • Reducing weight of any moving parts • Switching machine off when not in use. 2 Allow any other valid method of reducing energy loss. 11(d)(v) Factors will include: • Cams allow for quick adjustment • Limited movement needed • Positive locking action is possible • No tools required 2 Allow any other valid reason. Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned 1 mark. 11(e)(i) Mechanical advantage of the compound pulley is 8/1 = 8 1 11(e)(ii) 1.5 kN = 1500N / 8 [1] = 187.5 N, [1] 0.1875 kN 2

This question in 0445/42 May/June 2018

1 Fig. 1 shows the rear derailleur gear on a cycle with a close up view of the gear cable. outer gear cable inner gear cable outer gear cable inner gear cable nylon lining Fig. 1 (a) Name the force that has been applied, when manufacturing the inner gear cable to keep the strands of cable in position. … [1] (b) The outer gear cable has a nylon lining. Give two benefits of using the nylon lining. 1 … 2 … [2] (c) Explain why small radius bends should be avoided in the gear cable when it is attached to the cycle. … … … [2]

5 marks

Mark scheme: 1(a) Torque or torsion 1 Allow twisting 1(b) Benefits of the nylon lining could include: • Reduce friction • Reduce the amount of lubrication required • Prevent water getting to inner cable • Prevent inner cable rubbing on outer 2 × 1 marks for suitable benefits 2 Allow any other valid benefit. E.g. lightweight, waterproof, flexible. 1(c) Small radius bends will restrict the cable and prevent efficient movement of the inner cable. Permanent distortion of the outer cable could result. Possibility of cable snapping. 2 Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned, 1 mark.

This question in 0445/43 May/June 2018

3 Hydraulic systems are now used for many applications rather than a control cable. State the force created in a hydraulic system. … [1]

1 marks

Mark scheme: 3 Compression 1

This question in 0445/43 May/June 2018

4 Fig. 2 shows the speed control lever on a wood turning lathe. Slow Fast Fig. 2 (a) Complete three of the labels to show the position of effort, load and fulcrum on the lever when it is used to change the speed of the lathe. [3] (b) State the order of lever used. … [1]

4 marks

Mark scheme: 4(a) 3 4(b) Second order lever 1 Accept 2nd class lever Fast Slow L F E

This question in 0445/43 May/June 2018

5 Choose from the terms below to complete the table. bevel gear idler gear rack and pinion worm gear Requirement Method Transfer drive through 90° with no change in speed Provide a large reduction in speed in a small space Make driver and driven shafts rotate in the same direction [3]

3 marks

Mark scheme: 5 Requirement Method Transfer drive through 90° with no change in speed bevel gear Provide a large reduction in speed in a small space worm gear Make driver and driven shafts rotate in the same direction idler gear 3

This question in 0445/43 May/June 2018

6 Fig. 3 shows a piece of rod with a square thread cut into it. 3 6 2519 Fig. 3 State the pitch of the thread. … [1]

1 marks

Mark scheme: 6 Thread pitch is 6 mm 1

This question in 0445/43 May/June 2018

11 Fig. 11 shows views of the chain drive on a cycle. 10 sprockets jockey wheels chain 2 chainrings Fig. 11 (a) (i) Describe two functions of the jockey wheels in the chain drive. 1 … … 2 … … [2] (ii) Calculate the number of gear ratios that are available on the cycle. … … [2] (iii) Name the factor, in addition to the number of sprockets and chainrings that will determine how far the cycle will travel for each rotation of the chainring. … [1] (b) (i) Explain why a chain should be lubricated. … … … [2] (ii) State why grease is not suitable for lubricating a chain. … (c) Fig. 12 shows three different types of bearing that can be used in a jockey wheel. rubber seal grooves R S T plain bearing – ceramic plain bearing – steel sealed ball bearing Fig. 12 (i) Give one reason for using a rubber seal either side of the bearing in type R. … … [1] (ii) The outer bearing face in type R has four grooves cut into the surface; this is a common feature when using plain bearings. State the reason for the grooves. … … [1] (iii) Give one benefit for each of the bearing types used in S and T. Bearing S … … Bearing T … … [2] (d) Fig. 13 shows the blade guide for a small bandsaw used for cutting timber. By turning handle A the guide can be raised or lowered to allow different thicknesses of timber to be cut. handle A visible part of mechanism blade guide saw table blade Fig. 13 (i) Name the mechanism used to raise and lower the blade guide when handle A is turned. … [2] (ii) State the conversion of motion which takes place when handle A is turned and the blade guide moves. … to … [2] (iii) When the bandsaw is in use there are energy losses. Name two ways in which the energy from the motor can be lost when the machine is in use. 1 … … 2 … … [2] (iv) Describe how energy loss in a powered machine can be reduced. … … … [2] (v) The guide fence for the saw is held securely in place by a cam lever shown in Fig. 14. unlocked locked position position cam profile Fig. 14 Explain why cams are often used where frequent adjustment is necessary. … … … [2] (e) Fig. 15 shows a compound pulley system. effort load Fig. 15 (i) State the mechanical advantage of the pulley system. … [1] (ii) Calculate the pulling force necessary to raise a load of 1.5 kN. … … … [2]

25 marks

Mark scheme: 11(a)(i) To tension the chain or take up excess chain length, 1 mark To guide the chain onto different sprockets, 1 mark 2 11(a)(ii) 2 chainrings × 10 sprockets, 1 mark = 20 gear ratios, 1 mark 2 Award 2 marks for 20 11(a)(iii) The diameter of the wheel will affect the distance travelled. 1 11(b)(i) Reasons for lubricating a chain include: • Reduce friction between rollers / links • Reduce wear of the chain • Keep water away from moving parts • Increase efficiency of the mechanism. 2 Allow any other valid reason. Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned 1 mark. 11(b)(ii) Grease would be too thick to get through to the inner sections of rollers. 1 11(c)(i) The rubber seals will: • Keep oil in place in the bearing • Keep dust / grit / water away from the bearing surfaces 1 11(c)(ii) The grooves act as a reservoir for the oil. They also allow grit / abrasive material to collect without damaging the bearing surface. 1 Allow mark for reference to oiling. 11(c)(iii) Benefit of type S: 1 mark • Simple design • Low cost • Easily replaced Benefit of type T: 1 mark • Reduced friction • Will take both axial and radial load • No maintenance required 2 Allow any other valid benefits. Do not allow the same benefit for both bearings. For T allow, ‘withstand force’. 11(d)(i) Rack and pinion, 1 mark for each 2 11(d)(ii) Rotary motion to linear motion, 1 mark for each 2 Allow ‘circular’ for ‘rotary’ Question Answer Marks Guidance 11(d)(iii) Energy losses can be through friction in bearings, sound, heat. 2 × 1 marks 2 11(d)(iv) Energy loss can be reduced by: • Use of efficient bearings to reduce friction • Lubrication • Reducing weight of any moving parts • Switching machine off when not in use. 2 Allow any other valid method of reducing energy loss. 11(d)(v) Factors will include: • Cams allow for quick adjustment • Limited movement needed • Positive locking action is possible • No tools required 2 Allow any other valid reason. Full explanation of a single point, 2 marks. Explanation that includes two points, 2 marks. One point mentioned 1 mark. 11(e)(i) Mechanical advantage of the compound pulley is 8/1 = 8 1 11(e)(ii) 1.5 kN = 1500N / 8 [1] = 187.5 N, [1] 0.1875 kN 2

This question in 0445/43 May/June 2018

4 Pneumatic cylinders can be used to produce motion. (a) Describe the difference between a single acting cylinder (SAC) and a double acting cylinder (DAC). … … … [2] (b) State the type of motion produced by a pneumatic cylinder. … [1]

3 marks

Mark scheme: 4(a) A single acting cylinder (SAC) is only air powered on the outstroke, it returns with spring pressure [1] A double acting cylinder (DAC) is air powered in both directions [1] 2 connections on each type SAC – 1 DAC – 2 4(b) Reciprocating motion is produced by a pne0umatic cylinder. 1

This question in 0445/41 Oct/Nov 2018

6 Fig. 3 shows three examples of a lever. claw hammer stapler spanner A B C Fig. 3 (a) State the order of lever used in each example. Lever A … Lever B … Lever C … [3] (b) State which of the three levers will not provide a mechanical advantage to the user. … [1]

4 marks

Mark scheme: 6(a) Lever A is 1st order (first class), lever B is 3rd order (third class), lever C is 2nd order (second class), 1 mark for each correct. 3 6(b) The stapler, lever B, 3rd order does not give a mechanical advantage. 1

This question in 0445/41 Oct/Nov 2018

8 (a) State the force that is applied to a screw as it is inserted into a piece of wood. … [1] (b) Explain why more care has to be taken when inserting brass screws into a piece of wood compared to steel screws. … … … [2]

3 marks

Mark scheme: 8(a) Torsion / torque is applied to a screw that is being inserted. 1 8(b) 1 mark each for any two of the factors below: • Brass is a softer / more malleable material than steel • The screw slot or pozidrive slot can easily be damaged • The body of the screw can fail / shear due to excessive torsion. 2 Allow ‘not as strong as steel’.

This question in 0445/41 Oct/Nov 2018

11 (a) (i) Give two reasons for using gears in a mechanism. 1 … … 2 … … [2] (ii) Fig. 8 shows a simple gear arrangement. 250t 10t driver gear not to scale Fig. 8 State the velocity ratio of the gear arrangement. … [1] (iii) If the output shaft rotates at 11.5 rpm calculate the rotational speed of the input shaft. … … [2] (iv) Fig. 9 shows a compound gear train that will give the same velocity ratio as the simple gear arrangement in Fig. 8. 12t driver 12t gear Fig. 9 Calculate the number of teeth on each of the larger gears. Each of the larger gears has the same number of teeth. … … … [2] (v) State one advantage of using the compound gear arrangement compared to the simple gear arrangement. … … [1] (vi) In a gear system the driver and driven gears have to be secured to prevent rotation on the shaft but must be removable for maintenance. Use sketches and notes to show a method of securing a gear onto a shaft that will allow for easy removal. [3] (vii) Give one factor that will reduce the energy demands of a gear system. … [1] (b) Fig. 10 shows a model hot air engine. The engine uses two cylinders and two pistons. 4 2 1 5 3 Fig. 10 (i) Complete the table below to identify parts of the hot air engine. One has been done for you. Number Component 3 Bell crank lever Linkage Crank web Crank pin [3] (ii) State the purpose of a bell crank lever. … [1] (iii) Lubrication holes are provided as shown in Fig. 11. lubrication holes Fig. 11 Explain why lubrication is important in a mechanism. … … … [2] (iv) Fig. 12 shows the piston attached to the connecting rod, which is the input; movement of the flywheel is the output. flywheel piston connecting rod Fig. 12 Give the conversion of motion that is produced when the engine is working. … to … [2] (c) Mechanisms can use belts to transfer motion from one shaft to another. Fig. 13 shows two types of drive belt. belt A belt B Fig. 13 (i) Give one different benefit for each type of belt. Belt A … … Belt B … … [2] (ii) Drive belts need a tensioning device when in use. Use sketches and notes to show one method of tensioning a drive belt. [3]

25 marks

Mark scheme: 11(a)(i) Reasons for using gears will include: • Change direction of rotation • Increase or decrease speed • Increase mechanical advantage • Change angle of rotation / axis of motion • To drive one shaft from another / connect two shafts • Provide a positive method of drive. 2 Allow any other valid reason. 11(a)(ii) Velocity ratio = driver / driven = 10 / 250 = 1:25 0.04 1 Allow 1:25 11(a)(iii) Input speed = output / VR = 11.5 / 0.04 [1] = 287.5 rpm [1] 2 Award 2 marks for answer with no working. Allow output × gear ratio, 11.5 × 25. 11(a)(iv) Required ratio is 25:1 so both parts of compound gear train must be 5:1 [1] Larger gears are 12 × 5 = 60 t [1] 2 Allow ecf on ratio required. 11(a)(v) Advantages could be more compact than simple gear arrangement, lower cost than using a very large spur gear. 1 11(a)(vi) Positive method of securing used, keyway / flat / hole in shaft. [1] Removable method. [1] Clear annotation / sketches to show how the method works. [1] 3 Accept any practical method. 11(a)(vii) Factors will include: • Weight reduction in components • Efficient lubrication system • Design of teeth to give minimum contact area • Reduced friction in shafts. 1 Allow any other valid factor. Question Answer Marks Guidance 11(b)(i) 3 1 mark for each correct, 3 × 1 11(b)(ii) A bell crank lever will change motion through an angle 1 Give mark for understanding shown. 11(b)(iii) Lubrication is used to: • Reduce friction • Cool components • Reduce wear in component surfaces • Reduce corrosion • Keep the component surfaces apart. 2 Allow 2 marks for a single point well explained. 2 marks for two points in less depth. 11(b)(iv) Reciprocating to Rotary 2 1 mark for each term. 11(c)(i) Belt A can be fitted regardless of relative position of the pulleys Grooves help to prevent lateral / sideways movement of belt. Belt B does not allow any slipping. Pulleys are kept at exactly the same relative spacing. 2 Accept any other valid benefits. 11(c)(ii) Functional idea [1] Adjustable to compensate for belt stretching [1] Clear communication in the response [1] 3 3 1 4 5 Bell crank lever Linkage Crank web Crank pin

This question in 0445/41 Oct/Nov 2018

4 Pneumatic cylinders can be used to produce motion. (a) Describe the difference between a single acting cylinder (SAC) and a double acting cylinder (DAC). … … … [2] (b) State the type of motion produced by a pneumatic cylinder. … [1]

3 marks

Mark scheme: 4(a) A single acting cylinder (SAC) is only air powered on the outstroke, it returns with spring pressure [1] A double acting cylinder (DAC) is air powered in both directions [1] 2 connections on each type SAC – 1 DAC – 2 4(b) Reciprocating motion is produced by a pne0umatic cylinder. 1

This question in 0445/42 Oct/Nov 2018

6 Fig. 3 shows three examples of a lever. claw hammer stapler spanner A B C Fig. 3 (a) State the order of lever used in each example. Lever A … Lever B … Lever C … [3] (b) State which of the three levers will not provide a mechanical advantage to the user. … [1]

4 marks

Mark scheme: 6(a) Lever A is 1st order (first class), lever B is 3rd order (third class), lever C is 2nd order (second class), 1 mark for each correct. 3 6(b) The stapler, lever B, 3rd order does not give a mechanical advantage. 1

This question in 0445/42 Oct/Nov 2018

8 (a) State the force that is applied to a screw as it is inserted into a piece of wood. … [1] (b) Explain why more care has to be taken when inserting brass screws into a piece of wood compared to steel screws. … … … [2]

3 marks

Mark scheme: 8(a) Torsion / torque is applied to a screw that is being inserted. 1 8(b) 1 mark each for any two of the factors below: • Brass is a softer / more malleable material than steel • The screw slot or pozidrive slot can easily be damaged • The body of the screw can fail / shear due to excessive torsion. 2 Allow ‘not as strong as steel’.

This question in 0445/42 Oct/Nov 2018

11 (a) (i) Give two reasons for using gears in a mechanism. 1 … … 2 … … [2] (ii) Fig. 8 shows a simple gear arrangement. 250t 10t driver gear not to scale Fig. 8 State the velocity ratio of the gear arrangement. … [1] (iii) If the output shaft rotates at 11.5 rpm calculate the rotational speed of the input shaft. … … [2] (iv) Fig. 9 shows a compound gear train that will give the same velocity ratio as the simple gear arrangement in Fig. 8. 12t driver 12t gear Fig. 9 Calculate the number of teeth on each of the larger gears. Each of the larger gears has the same number of teeth. … … … [2] (v) State one advantage of using the compound gear arrangement compared to the simple gear arrangement. … … [1] (vi) In a gear system the driver and driven gears have to be secured to prevent rotation on the shaft but must be removable for maintenance. Use sketches and notes to show a method of securing a gear onto a shaft that will allow for easy removal. [3] (vii) Give one factor that will reduce the energy demands of a gear system. … [1] (b) Fig. 10 shows a model hot air engine. The engine uses two cylinders and two pistons. 4 2 1 5 3 Fig. 10 (i) Complete the table below to identify parts of the hot air engine. One has been done for you. Number Component 3 Bell crank lever Linkage Crank web Crank pin [3] (ii) State the purpose of a bell crank lever. … [1] (iii) Lubrication holes are provided as shown in Fig. 11. lubrication holes Fig. 11 Explain why lubrication is important in a mechanism. … … … [2] (iv) Fig. 12 shows the piston attached to the connecting rod, which is the input; movement of the flywheel is the output. flywheel piston connecting rod Fig. 12 Give the conversion of motion that is produced when the engine is working. … to … [2] (c) Mechanisms can use belts to transfer motion from one shaft to another. Fig. 13 shows two types of drive belt. belt A belt B Fig. 13 (i) Give one different benefit for each type of belt. Belt A … … Belt B … … [2] (ii) Drive belts need a tensioning device when in use. Use sketches and notes to show one method of tensioning a drive belt. [3]

25 marks

Mark scheme: 11(a)(i) Reasons for using gears will include: • Change direction of rotation • Increase or decrease speed • Increase mechanical advantage • Change angle of rotation / axis of motion • To drive one shaft from another / connect two shafts • Provide a positive method of drive. 2 Allow any other valid reason. 11(a)(ii) Velocity ratio = driver / driven = 10 / 250 = 1:25 0.04 1 Allow 1:25 11(a)(iii) Input speed = output / VR = 11.5 / 0.04 [1] = 287.5 rpm [1] 2 Award 2 marks for answer with no working. Allow output × gear ratio, 11.5 × 25. 11(a)(iv) Required ratio is 25:1 so both parts of compound gear train must be 5:1 [1] Larger gears are 12 × 5 = 60 t [1] 2 Allow ecf on ratio required. 11(a)(v) Advantages could be more compact than simple gear arrangement, lower cost than using a very large spur gear. 1 11(a)(vi) Positive method of securing used, keyway / flat / hole in shaft. [1] Removable method. [1] Clear annotation / sketches to show how the method works. [1] 3 Accept any practical method. 11(a)(vii) Factors will include: • Weight reduction in components • Efficient lubrication system • Design of teeth to give minimum contact area • Reduced friction in shafts. 1 Allow any other valid factor. Question Answer Marks Guidance 11(b)(i) 3 1 mark for each correct, 3 × 1 11(b)(ii) A bell crank lever will change motion through an angle 1 Give mark for understanding shown. 11(b)(iii) Lubrication is used to: • Reduce friction • Cool components • Reduce wear in component surfaces • Reduce corrosion • Keep the component surfaces apart. 2 Allow 2 marks for a single point well explained. 2 marks for two points in less depth. 11(b)(iv) Reciprocating to Rotary 2 1 mark for each term. 11(c)(i) Belt A can be fitted regardless of relative position of the pulleys Grooves help to prevent lateral / sideways movement of belt. Belt B does not allow any slipping. Pulleys are kept at exactly the same relative spacing. 2 Accept any other valid benefits. 11(c)(ii) Functional idea [1] Adjustable to compensate for belt stretching [1] Clear communication in the response [1] 3 3 1 4 5 Bell crank lever Linkage Crank web Crank pin

This question in 0445/42 Oct/Nov 2018

4 Pneumatic cylinders can be used to produce motion. (a) Describe the difference between a single acting cylinder (SAC) and a double acting cylinder (DAC). … … … [2] (b) State the type of motion produced by a pneumatic cylinder. … [1]

3 marks

Mark scheme: 4(a) A single acting cylinder (SAC) is only air powered on the outstroke, it returns with spring pressure [1] A double acting cylinder (DAC) is air powered in both directions [1] 2 connections on each type SAC – 1 DAC – 2 4(b) Reciprocating motion is produced by a pne0umatic cylinder. 1

This question in 0445/43 Oct/Nov 2018

6 Fig. 3 shows three examples of a lever. claw hammer stapler spanner A B C Fig. 3 (a) State the order of lever used in each example. Lever A … Lever B … Lever C … [3] (b) State which of the three levers will not provide a mechanical advantage to the user. … [1]

4 marks

Mark scheme: 6(a) Lever A is 1st order (first class), lever B is 3rd order (third class), lever C is 2nd order (second class), 1 mark for each correct. 3 6(b) The stapler, lever B, 3rd order does not give a mechanical advantage. 1

This question in 0445/43 Oct/Nov 2018

8 (a) State the force that is applied to a screw as it is inserted into a piece of wood. … [1] (b) Explain why more care has to be taken when inserting brass screws into a piece of wood compared to steel screws. … … … [2]

3 marks

Mark scheme: 8(a) Torsion / torque is applied to a screw that is being inserted. 1 8(b) 1 mark each for any two of the factors below: • Brass is a softer / more malleable material than steel • The screw slot or pozidrive slot can easily be damaged • The body of the screw can fail / shear due to excessive torsion. 2 Allow ‘not as strong as steel’.

This question in 0445/43 Oct/Nov 2018

11 (a) (i) Give two reasons for using gears in a mechanism. 1 … … 2 … … [2] (ii) Fig. 8 shows a simple gear arrangement. 250t 10t driver gear not to scale Fig. 8 State the velocity ratio of the gear arrangement. … [1] (iii) If the output shaft rotates at 11.5 rpm calculate the rotational speed of the input shaft. … … [2] (iv) Fig. 9 shows a compound gear train that will give the same velocity ratio as the simple gear arrangement in Fig. 8. 12t driver 12t gear Fig. 9 Calculate the number of teeth on each of the larger gears. Each of the larger gears has the same number of teeth. … … … [2] (v) State one advantage of using the compound gear arrangement compared to the simple gear arrangement. … … [1] (vi) In a gear system the driver and driven gears have to be secured to prevent rotation on the shaft but must be removable for maintenance. Use sketches and notes to show a method of securing a gear onto a shaft that will allow for easy removal. [3] (vii) Give one factor that will reduce the energy demands of a gear system. … [1] (b) Fig. 10 shows a model hot air engine. The engine uses two cylinders and two pistons. 4 2 1 5 3 Fig. 10 (i) Complete the table below to identify parts of the hot air engine. One has been done for you. Number Component 3 Bell crank lever Linkage Crank web Crank pin [3] (ii) State the purpose of a bell crank lever. … [1] (iii) Lubrication holes are provided as shown in Fig. 11. lubrication holes Fig. 11 Explain why lubrication is important in a mechanism. … … … [2] (iv) Fig. 12 shows the piston attached to the connecting rod, which is the input; movement of the flywheel is the output. flywheel piston connecting rod Fig. 12 Give the conversion of motion that is produced when the engine is working. … to … [2] (c) Mechanisms can use belts to transfer motion from one shaft to another. Fig. 13 shows two types of drive belt. belt A belt B Fig. 13 (i) Give one different benefit for each type of belt. Belt A … … Belt B … … [2] (ii) Drive belts need a tensioning device when in use. Use sketches and notes to show one method of tensioning a drive belt. [3]

25 marks

Mark scheme: 11(a)(i) Reasons for using gears will include: • Change direction of rotation • Increase or decrease speed • Increase mechanical advantage • Change angle of rotation / axis of motion • To drive one shaft from another / connect two shafts • Provide a positive method of drive. 2 Allow any other valid reason. 11(a)(ii) Velocity ratio = driver / driven = 10 / 250 = 1:25 0.04 1 Allow 1:25 11(a)(iii) Input speed = output / VR = 11.5 / 0.04 [1] = 287.5 rpm [1] 2 Award 2 marks for answer with no working. Allow output × gear ratio, 11.5 × 25. 11(a)(iv) Required ratio is 25:1 so both parts of compound gear train must be 5:1 [1] Larger gears are 12 × 5 = 60 t [1] 2 Allow ecf on ratio required. 11(a)(v) Advantages could be more compact than simple gear arrangement, lower cost than using a very large spur gear. 1 11(a)(vi) Positive method of securing used, keyway / flat / hole in shaft. [1] Removable method. [1] Clear annotation / sketches to show how the method works. [1] 3 Accept any practical method. 11(a)(vii) Factors will include: • Weight reduction in components • Efficient lubrication system • Design of teeth to give minimum contact area • Reduced friction in shafts. 1 Allow any other valid factor. Question Answer Marks Guidance 11(b)(i) 3 1 mark for each correct, 3 × 1 11(b)(ii) A bell crank lever will change motion through an angle 1 Give mark for understanding shown. 11(b)(iii) Lubrication is used to: • Reduce friction • Cool components • Reduce wear in component surfaces • Reduce corrosion • Keep the component surfaces apart. 2 Allow 2 marks for a single point well explained. 2 marks for two points in less depth. 11(b)(iv) Reciprocating to Rotary 2 1 mark for each term. 11(c)(i) Belt A can be fitted regardless of relative position of the pulleys Grooves help to prevent lateral / sideways movement of belt. Belt B does not allow any slipping. Pulleys are kept at exactly the same relative spacing. 2 Accept any other valid benefits. 11(c)(ii) Functional idea [1] Adjustable to compensate for belt stretching [1] Clear communication in the response [1] 3 3 1 4 5 Bell crank lever Linkage Crank web Crank pin

This question in 0445/43 Oct/Nov 2018

6 (a) Give one specific use for each of the following types of gear. Bevel gear … … Rack and pinion … … Worm gear … … [3] (b) Fig. 3 shows a rack and pinion gear system. Fig. 3 Describe a change to the system that will allow the direction of movement of the rack to be reversed with the pinion still rotating in the same direction. … … … [2]

5 marks

Mark scheme: 6(a) Bevel gear – Any use that requires drive to turn through 90º, can be used to change output speed. [1] Rack and pinion – steering, pillar drill operation, any use requiring rotary to linear conversion of movement. [1] Worm gear – any use requiring a large reduction in speed, winch, lift / elevator gears, change in direction of motion or increase in torque. [1] 3 type. Allow clear description of the specific function of the gear. 6(b) Direction can be reversed by: • Adding an idler gear [1] between the pinion and the rack [1]. • Changing the position of the rack [1] to above the pinion gear [1]. 2

This question in 0445/41 May/June 2019

7 Use sketches and notes to show what is meant by a compound gear arrangement. [2]

2 marks

Mark scheme: 7 Drawing / notes showing two gears fixed to the same shaft [1] Input and output gears shown [1]. 2 input/driver gear output/driven gear two gears fixed together on single shaft

This question in 0445/41 May/June 2019

10 Fig. 11 shows a ‘sit-on’ toy digger for a child. The digger is operated by two levers, A and B. Lever A controls the angle of the scoop and lever B will raise and lower the scoop. handle B handle A pivot C fixed joint pivot scoop Fig. 11 (a) (i) State the class of lever operated by handle A. … [1] (ii) State the class of lever operated by handle B. … [1] (iii) Describe the result of pushing forward on handle A. … … … [2] (iv) The seat and mechanism rotate at point C. Use sketches and notes to show how point C could be designed to provide support and allow for rotation. Name all components and materials used. [4] (b) Two types of jack are shown in Fig. 12. vertical movement – 5 mm for 360° rotation of handle handle rotates horizontally release end of handle to valve centre of jack – 300 mm hydraulic jack screw jack Fig. 12 (i) State the conversion of motion used in the hydraulic jack. … to … [2] (ii) Describe the purpose of the release valve in a hydraulic jack. … … … [2] (iii) Calculate the mechanical advantage given by the screw jack. Use the formula circumference = 2 π r for the distance moved by the handle for one full rotation. … … … … [3] (iv) Fig. 13 shows the ratchet and pawl mechanism used on the screw jack operating handle. handle fixing point ratchet pawl ball bearing race Fig. 13 Explain why this mechanism is used. … … … [2] (v) Give two other uses for a ratchet and pawl mechanism. 1 … 2 … [2] (vi) Explain why the ball bearing race will improve the efficiency of the jack. … … … [2] (c) (i) Use sketches and notes to show what is meant by the pitch of a thread. [2] (ii) Screw threads are often used in measuring instruments such as the micrometer shown in Fig. 14. distance being measured thimble anvil spindle 5 0 0 5 45 section through thimble to show thread Fig. 14 Two rotations of the micrometer thimble will result in the gap between the anvil and spindle moving 1 mm. State the pitch of the thread used in the micrometer. … [1] (d) Fig. 15 shows part of the gear system from a rechargeable electric drill. plain bearings Ø38 plain bearings Fig. 15 Give one reason why plain bearings are suitable for the gear system. … … [1]

25 marks

Mark scheme: 10(a)(i) Lever A is second order / class 2 1 10(a)(ii) Lever B is third order / class 3 1 10(a)(iii) Pushing forward on lever A will rotate / move the bucket [1], in a clockwise direction (oscillation) [1]. 2 Allow marks for understanding shown 10(a)(iv) Bearing used to provide rotation, 1 mark Type of bearing named / defined, 1 mark Functional method used, 1 mark Components / materials named, 1 mark. 4 Allow 1 mark for wheels used on legs for rotation. 10(b)(i) Conversion of motion is oscillating [1] to linear [1] 2 10(b)(ii) Operating the release valve will allow hydraulic fluid to return to the reservoir [1], causing the jack to lower [1]. The release valve will prevent any backflow / return of fluid to the master cylinder [1]. Valve can control descent speed of the jack [1]. 2 Any two points included in description, 2 marks. 10(b)(iii) MA = distance moved by effort / distance moved by load Distance moved by effort = 2 × π × 300, 1 mark =1884.96 1 mark 1884.96 / 5, = 376.99, 1 mark 3 Award marks for correct answer with no working. 10(b)(iv) The ratchet and pawl will allow less than a complete turn of the bar to be used [1] this is useful in restricted space [1]. 2 Both points needed for two marks. Allow prevention of accidental lowering of jack. Question Answer Marks Guidance 10(b)(v) Accept any valid use of ratchet and pawl: • Screwdriver • Wrench • Cycle freewheel • Luggage straps • Clock • Hoist 2 × 1 marks 2 10(b)(vi) The load on the jack will cause friction on the rotating parts [1] The ball bearing grace can withstand a large load [1] The bearing race will help to overcome frictional losses [1] making the jack handle easier to turn [1]. 2 Two points in explanation, 2 marks Allow 2 marks for full explanation of a single point. 10(c)(i) External surface of thread indicated [1] pitch indicated [1]. 2 10(c)(ii) Pitch of thread is 0.5 mm 1 10(d) Reasons for using plain bearings include: • Lower cost than ball bearings • Not a large load on the bearing • Limited space • Ease of manufacture and assembly. 1 mark for valid reason given. 1 pitch

This question in 0445/41 May/June 2019

4 Give two reasons for using gears in a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 4 Reasons for using gears will include: • Changing direction of motion, clockwise / anticlockwise • Changing speed of rotation • Change in mechanical advantage • Connecting power source to a mechanism • Changing direction of motion, angle between two shafts • Do not slip like a belt and pulley. • Increase torque 2 × 1 marks for suitable reasons. 2 Allow welding / permanent fixing.

This question in 0445/42 May/June 2019

5 Use sketches and notes to show one method of fixing a spur gear to a shaft without allowing the spur gear to rotate on the shaft. [2]

2 marks

Mark scheme: 5 Methods of locking to shaft will include: • Keyway • Splined shaft • Flat on shaft with grub screw • Interference fit. Clear sketch description of changes to shaft/spur gear, 1 mark Functional method, 1 mark. 2 No mark for gluing

This question in 0445/42 May/June 2019

6 State the conversion of motion that takes place in the following mechanisms. Cam and follower … to … Screw thread and nut … to … [4]

4 marks

Mark scheme: 6 Rotary [1] to reciprocating [1] Rotary [1] to linear [1] 4

This question in 0445/42 May/June 2019

9 Fig. 9 shows a vee belt and pulley system. section through pulley and belt Fig. 9 (a) (i) State one advantage of this system over a flat belt. … [1] (ii) Use sketches and notes to show a method of adjusting the tension of the vee belt without moving either of the pulleys. [3] (b) Fig. 10 shows a pulley system used for lifting heavy loads. Fig. 10 (i) State the velocity ratio of the pulley system. … [1] (ii) Explain why the actual mechanical advantage of the pulley system will not be as high as the velocity ratio. … … … [2] (iii) The pulleys shown in Fig. 10 are made from hardwood with a hole drilled through to act as a plain bearing. Fig. 11 shows details of one of the pulleys. Fig. 11 Use sketches and notes on Fig. 11 to show an alternative bearing in position that will increase the actual mechanical advantage of the system. [2] (c) Fig. 12 shows a foot pump for inflating car tyres. foot operated lever cylinders X connecting rods Fig. 12a Fig. 12b (i) Label the positions of the effort, load and fulcrum on the foot operated lever in Fig. 12b. [3] (ii) Explain why the joint at X cannot be a fixed joint. … … … [2] (iii) When the foot operated lever is pressed the connecting rods will move into the cylinders to compress the air. State the type of motion that is caused when this happens. … [1] (iv) A similar motion could be provided by a crank and slider mechanism. Use sketches and notes to describe the operation of a crank and slider mechanism. [3] (d) Fig. 13 shows a cam and follower. 13.25 10 10 Fig. 13 (i) Name the type of follower shown in Fig. 13. … [1] (ii) Calculate the ‘lift’ of the cam. … [1] (iii) Starting from the given position, use the words dwell, rise and fall to complete the table describing follower movement as the cam rotates. Angle moved by cam Follower movement 90° 180° 270° 360° [3] (iv) A different type of follower is shown in Fig. 14. Fig. 14 Describe the result of having the cam follower offset from the centre of the cam profile. … … … [2]

25 marks

Mark scheme: 9(a)(i) Advantages will include: • Less chance of slipping / belt coming off • Less tensioning required than on a flat belt • Can help to dampen vibration • More power can be transmitted 1 mark for suitable advantage 1 Question Answer Marks Guidance 9(a)(ii) Spring loaded tension device or jockey wheel / idler that is in contact with the belt and can be adjusted. Valid principal used, 1 mark Clear drawing / notes, 1 mark Neither pulley has to be moved, 1 mark. 3 9(b)(i) Velocity ratio is 4. 1 No mark for 1:4 or 1/4 9(b)(ii) Frictional losses will reduce the mechanical advantage of the system. Sound / heat produced in each pulley when operated will have an effect. 2 Explanation with two points included, 2 marks. Allow 2 marks for a single point well explained. 9(b)(iii) Addition of a named type of bearing, 1 mark Position of bearing clear from sketches / notes, 1 mark. 2 9(c)(i) I mark for each correctly placed label 3 9(c)(ii) Joint X has to pivot to allow the connecting rods to move into the cylinder, 1 mark. If the joint was fixed the mechanism could not operate., 1 mark 2 9(c)(iii) Reciprocating motion, 1 mark. 1 Question Answer Marks Guidance 9(c)(iv) Rotation of crank described [1] Slider movement described [1] Functional mechanism [1] 3 9(d)(i) Roller follower [1] 1 9(d)(ii) The lift of the cam is 3.25mm. 1 9(d)(iii) 1 mark for ‘fall’ 1 mark for both ‘dwell’ stages correct 1 mark for ‘rise’ 3 9(d)(iv) The cam follower will rotate in its guide, 1 mark Wear in the guide will be reduced, 1 mark. 2 Angle moved by cam Follower movement 90º 180º 270º 360º fall dwell rise dwell

This question in 0445/42 May/June 2019

6 (a) Give one specific use for each of the following types of gear. Bevel gear … … Rack and pinion … … Worm gear … … [3] (b) Fig. 3 shows a rack and pinion gear system. Fig. 3 Describe a change to the system that will allow the direction of movement of the rack to be reversed with the pinion still rotating in the same direction. … … … [2]

5 marks

Mark scheme: 6(a) Bevel gear – Any use that requires drive to turn through 90º, can be used to change output speed. [1] Rack and pinion – steering, pillar drill operation, any use requiring rotary to linear conversion of movement. [1] Worm gear – any use requiring a large reduction in speed, winch, lift / elevator gears, change in direction of motion or increase in torque. [1] 3 type. Allow clear description of the specific function of the gear. 6(b) Direction can be reversed by: • Adding an idler gear [1] between the pinion and the rack [1]. • Changing the position of the rack [1] to above the pinion gear [1]. 2

This question in 0445/43 May/June 2019

7 Use sketches and notes to show what is meant by a compound gear arrangement. [2]

2 marks

Mark scheme: 7 Drawing / notes showing two gears fixed to the same shaft [1] Input and output gears shown [1]. 2 input/driver gear output/driven gear two gears fixed together on single shaft

This question in 0445/43 May/June 2019

10 Fig. 11 shows a ‘sit-on’ toy digger for a child. The digger is operated by two levers, A and B. Lever A controls the angle of the scoop and lever B will raise and lower the scoop. handle B handle A pivot C fixed joint pivot scoop Fig. 11 (a) (i) State the class of lever operated by handle A. … [1] (ii) State the class of lever operated by handle B. … [1] (iii) Describe the result of pushing forward on handle A. … … … [2] (iv) The seat and mechanism rotate at point C. Use sketches and notes to show how point C could be designed to provide support and allow for rotation. Name all components and materials used. [4] (b) Two types of jack are shown in Fig. 12. vertical movement – 5 mm for 360° rotation of handle handle rotates horizontally release end of handle to valve centre of jack – 300 mm hydraulic jack screw jack Fig. 12 (i) State the conversion of motion used in the hydraulic jack. … to … [2] (ii) Describe the purpose of the release valve in a hydraulic jack. … … … [2] (iii) Calculate the mechanical advantage given by the screw jack. Use the formula circumference = 2 π r for the distance moved by the handle for one full rotation. … … … … [3] (iv) Fig. 13 shows the ratchet and pawl mechanism used on the screw jack operating handle. handle fixing point ratchet pawl ball bearing race Fig. 13 Explain why this mechanism is used. … … … [2] (v) Give two other uses for a ratchet and pawl mechanism. 1 … 2 … [2] (vi) Explain why the ball bearing race will improve the efficiency of the jack. … … … [2] (c) (i) Use sketches and notes to show what is meant by the pitch of a thread. [2] (ii) Screw threads are often used in measuring instruments such as the micrometer shown in Fig. 14. distance being measured thimble anvil spindle 5 0 0 5 45 section through thimble to show thread Fig. 14 Two rotations of the micrometer thimble will result in the gap between the anvil and spindle moving 1 mm. State the pitch of the thread used in the micrometer. … [1] (d) Fig. 15 shows part of the gear system from a rechargeable electric drill. plain bearings Ø38 plain bearings Fig. 15 Give one reason why plain bearings are suitable for the gear system. … … [1]

25 marks

Mark scheme: 10(a)(i) Lever A is second order / class 2 1 10(a)(ii) Lever B is third order / class 3 1 10(a)(iii) Pushing forward on lever A will rotate / move the bucket [1], in a clockwise direction (oscillation) [1]. 2 Allow marks for understanding shown 10(a)(iv) Bearing used to provide rotation, 1 mark Type of bearing named / defined, 1 mark Functional method used, 1 mark Components / materials named, 1 mark. 4 Allow 1 mark for wheels used on legs for rotation. 10(b)(i) Conversion of motion is oscillating [1] to linear [1] 2 10(b)(ii) Operating the release valve will allow hydraulic fluid to return to the reservoir [1], causing the jack to lower [1]. The release valve will prevent any backflow / return of fluid to the master cylinder [1]. Valve can control descent speed of the jack [1]. 2 Any two points included in description, 2 marks. 10(b)(iii) MA = distance moved by effort / distance moved by load Distance moved by effort = 2 × π × 300, 1 mark =1884.96 1 mark 1884.96 / 5, = 376.99, 1 mark 3 Award marks for correct answer with no working. 10(b)(iv) The ratchet and pawl will allow less than a complete turn of the bar to be used [1] this is useful in restricted space [1]. 2 Both points needed for two marks. Allow prevention of accidental lowering of jack. Question Answer Marks Guidance 10(b)(v) Accept any valid use of ratchet and pawl: • Screwdriver • Wrench • Cycle freewheel • Luggage straps • Clock • Hoist 2 × 1 marks 2 10(b)(vi) The load on the jack will cause friction on the rotating parts [1] The ball bearing grace can withstand a large load [1] The bearing race will help to overcome frictional losses [1] making the jack handle easier to turn [1]. 2 Two points in explanation, 2 marks Allow 2 marks for full explanation of a single point. 10(c)(i) External surface of thread indicated [1] pitch indicated [1]. 2 10(c)(ii) Pitch of thread is 0.5 mm 1 10(d) Reasons for using plain bearings include: • Lower cost than ball bearings • Not a large load on the bearing • Limited space • Ease of manufacture and assembly. 1 mark for valid reason given. 1 pitch

This question in 0445/43 May/June 2019

4 Fig. 1 shows a mechanism used to manually operate a railway signal. load cable to B signal cable operated A arms signals A B cable link to signal box Fig. 1 (a) The cable link is operated by a lever in a signal box. (i) State the order of lever used at A. … [1] (ii) Name the force acting in the cable when the signal is operated. … [1] (iii) Describe the purpose of counterbalance B. … … … [2] (b) Give two reasons why modern signalling systems are electronic rather than mechanical. 1 … 2 … [2]

6 marks

Mark scheme: 4(a)(i) Lever A is second order [1] 1 4(a)(ii) Tension 1 4(a)(iii) Counterweight B ensures that the lever arm returns to its resting position [1] when the tension in the cable is removed [1] 2 Allow marks for understanding shown. 4(b) Reasons could include: • More complex signals now required • Faster to change signal or modify function • No movement involved • Can be automated • Reduced maintenance 2 × 1 marks 2 Accept any other valid reason.

This question in 0445/41 Oct/Nov 2019

5 Fig. 2 shows two eccentrics on a locomotive axle. Fig. 2 (a) Give the conversion of motion produced by an eccentric. … to … [2] (b) Name one other mechanism that will produce the same conversion of motion. … [1]

3 marks

Mark scheme: 5(a) Rotary motion 1 mark to reciprocating motion 1 mark 2 5(b) • Crank and slider. • Cam and follower 1 Accept crankshaft Allow ecf from 5(b)

This question in 0445/41 Oct/Nov 2019

10 Fig. 8 shows an arrangement of gears driven by a small electric motor. C 60t B 16t E 60t A D 16t Fig. 8 (a) (i) State the name of gear A. … [1] (ii) Give two reasons for using this type of gear. 1 … 2 … [2] (iii) Gear B is an idler gear. Give two reasons for using an idler gear. 1 … 2 … [2] (iv) Calculate the gear ratio between the driver gear A and the driven gear E. … … … … [3] (v) The gears are all made from nylon. State two properties of nylon that make it suitable for use in small gear systems. 1 … 2 … [2] (b) Fig. 9 shows a chain and sprocket drive. Fig. 9 Use sketches and notes to show one method of adjusting the tension on the chain. [3] (c) Mechanisms can be powered in a number of ways. (i) State one safety precaution for each of the power sources given below. Electricity … Natural gas … Steam … Compressed air … [4] (ii) Describe the problems associated with the storage of electrical energy. … … … … [3] (iii) Explain how electronics and compressed air can be combined in a pneumatic system. … … … … [3] (d) Fig. 10 shows a gravity feed oil reservoir fitted on a steam engine. The lubricating oil in the reservoir falls onto the shaft and bearings below. oil reservoir bearings shaft Fig. 10 Give two drawbacks of a gravity feed oil reservoir. 1 … 2 … [2]

25 marks

Mark scheme: 10(a)(i) Gear A is a worm gear 1 10(a)(ii) Worm gears are used to: • Give large reduction of speed in a small space • Prevent reverse action / can only be turned in one direction • Transfer torque effectively 2 × 1 marks 2 10(a)(iii) An idler gear is used to: • Transfer drive from a driver gear to other gears in a train • Reverse the direction of motion without affecting speed of rotation • In a softer material as a sacrificial gear that can be easily replaced 2 × 1 marks 2 Allow ‘to provide space between other gears’ 10(a)(iv) Gear A to gear C is 60:1 reduction, 1 mark Gear D to gear E is 60 / 16:1 reduction = 3.75:1, 1 mark Final gear ratio is 60 × 3.75 = 225:1, 1 mark 3 10(a)(v) Properties of nylon include: • No lubrication required • Quiet in operation • Will resist chemicals • Can be moulded in one piece rather that teeth being cut individually 2 × 1 marks 2 Question Answer Marks Guidance 10(b) Tensioning can be achieved in two ways: • Moving the two gears further apart • Applying pressure to the chain with a pad or jockey wheel Valid principal used, 1 mark Clear sketches / notes, 1 mark Fixing methods / extra parts clearly shown / described, 1 mark 3 10(c)(i) Safety considerations could be: • Electricity – fuse / circuit breaker / insulation / earth system • Natural gas – pressure kept to a safe level, ensuring no leaks • Steam – boilers tested regularly, pipes checked for leaks, pressure regulator or safety valve • Compressed air – pressure reduced to a safe level, all components fixed down before testing a circuit 4 Allow any other safety precautions for each of the power sources. 10(c)(ii) Storage of electricity: • Currently only available in the form of batteries • Batteries can be bulky and costly • Safety considerations of batteries overheating and causing fires. • Not enough batteries are available for windy / sunny days when surplus electricity is produced 3 Explanation with three points, 3 marks Two points with no justification, 2 marks Allow 2 marks for a single point fully explained. Single point unjustified, 1 mark 10(c)(iii) Use of solenoid valves for switching and reed switch cylinders for sensing the position of pistons Computer systems / programmable logic units can control the pneumatic components 3 Principal shown, 1 mark Two items shown and clearly drawn / explained, 2 marks Allow 2 marks for clear drawing / notes on a single aspect. 10(d) Drawbacks of oil reservoir could be: • Needs regular filling • Time consuming • As bearings wear more oil is used • Oil is lost 2 × 1 marks 2

This question in 0445/41 Oct/Nov 2019

4 Fig. 1 shows a mechanism used to manually operate a railway signal. load cable to B signal cable operated A arms signals A B cable link to signal box Fig. 1 (a) The cable link is operated by a lever in a signal box. (i) State the order of lever used at A. … [1] (ii) Name the force acting in the cable when the signal is operated. … [1] (iii) Describe the purpose of counterbalance B. … … … [2] (b) Give two reasons why modern signalling systems are electronic rather than mechanical. 1 … 2 … [2]

6 marks

Mark scheme: 4(a)(i) Lever A is second order [1] 1 4(a)(ii) Tension 1 4(a)(iii) Counterweight B ensures that the lever arm returns to its resting position [1] when the tension in the cable is removed [1] 2 Allow marks for understanding shown. 4(b) Reasons could include: • More complex signals now required • Faster to change signal or modify function • No movement involved • Can be automated • Reduced maintenance 2 × 1 marks 2 Accept any other valid reason.

This question in 0445/42 Oct/Nov 2019

5 Fig. 2 shows two eccentrics on a locomotive axle. Fig. 2 (a) Give the conversion of motion produced by an eccentric. … to … [2] (b) Name one other mechanism that will produce the same conversion of motion. … [1]

3 marks

Mark scheme: 5(a) Rotary motion 1 mark to reciprocating motion 1 mark 2 5(b) • Crank and slider. • Cam and follower 1 Accept crankshaft Allow ecf from 5(b)

This question in 0445/42 Oct/Nov 2019

10 Fig. 8 shows an arrangement of gears driven by a small electric motor. C 60t B 16t E 60t A D 16t Fig. 8 (a) (i) State the name of gear A. … [1] (ii) Give two reasons for using this type of gear. 1 … 2 … [2] (iii) Gear B is an idler gear. Give two reasons for using an idler gear. 1 … 2 … [2] (iv) Calculate the gear ratio between the driver gear A and the driven gear E. … … … … [3] (v) The gears are all made from nylon. State two properties of nylon that make it suitable for use in small gear systems. 1 … 2 … [2] (b) Fig. 9 shows a chain and sprocket drive. Fig. 9 Use sketches and notes to show one method of adjusting the tension on the chain. [3] (c) Mechanisms can be powered in a number of ways. (i) State one safety precaution for each of the power sources given below. Electricity … Natural gas … Steam … Compressed air … [4] (ii) Describe the problems associated with the storage of electrical energy. … … … … [3] (iii) Explain how electronics and compressed air can be combined in a pneumatic system. … … … … [3] (d) Fig. 10 shows a gravity feed oil reservoir fitted on a steam engine. The lubricating oil in the reservoir falls onto the shaft and bearings below. oil reservoir bearings shaft Fig. 10 Give two drawbacks of a gravity feed oil reservoir. 1 … 2 … [2]

25 marks

Mark scheme: 10(a)(i) Gear A is a worm gear 1 10(a)(ii) Worm gears are used to: • Give large reduction of speed in a small space • Prevent reverse action / can only be turned in one direction • Transfer torque effectively 2 × 1 marks 2 10(a)(iii) An idler gear is used to: • Transfer drive from a driver gear to other gears in a train • Reverse the direction of motion without affecting speed of rotation • In a softer material as a sacrificial gear that can be easily replaced 2 × 1 marks 2 Allow ‘to provide space between other gears’ 10(a)(iv) Gear A to gear C is 60:1 reduction, 1 mark Gear D to gear E is 60 / 16:1 reduction = 3.75:1, 1 mark Final gear ratio is 60 × 3.75 = 225:1, 1 mark 3 10(a)(v) Properties of nylon include: • No lubrication required • Quiet in operation • Will resist chemicals • Can be moulded in one piece rather that teeth being cut individually 2 × 1 marks 2 Question Answer Marks Guidance 10(b) Tensioning can be achieved in two ways: • Moving the two gears further apart • Applying pressure to the chain with a pad or jockey wheel Valid principal used, 1 mark Clear sketches / notes, 1 mark Fixing methods / extra parts clearly shown / described, 1 mark 3 10(c)(i) Safety considerations could be: • Electricity – fuse / circuit breaker / insulation / earth system • Natural gas – pressure kept to a safe level, ensuring no leaks • Steam – boilers tested regularly, pipes checked for leaks, pressure regulator or safety valve • Compressed air – pressure reduced to a safe level, all components fixed down before testing a circuit 4 Allow any other safety precautions for each of the power sources. 10(c)(ii) Storage of electricity: • Currently only available in the form of batteries • Batteries can be bulky and costly • Safety considerations of batteries overheating and causing fires. • Not enough batteries are available for windy / sunny days when surplus electricity is produced 3 Explanation with three points, 3 marks Two points with no justification, 2 marks Allow 2 marks for a single point fully explained. Single point unjustified, 1 mark 10(c)(iii) Use of solenoid valves for switching and reed switch cylinders for sensing the position of pistons Computer systems / programmable logic units can control the pneumatic components 3 Principal shown, 1 mark Two items shown and clearly drawn / explained, 2 marks Allow 2 marks for clear drawing / notes on a single aspect. 10(d) Drawbacks of oil reservoir could be: • Needs regular filling • Time consuming • As bearings wear more oil is used • Oil is lost 2 × 1 marks 2

This question in 0445/42 Oct/Nov 2019

4 Fig. 1 shows a mechanism used to manually operate a railway signal. load cable to B signal cable operated A arms signals A B cable link to signal box Fig. 1 (a) The cable link is operated by a lever in a signal box. (i) State the order of lever used at A. … [1] (ii) Name the force acting in the cable when the signal is operated. … [1] (iii) Describe the purpose of counterbalance B. … … … [2] (b) Give two reasons why modern signalling systems are electronic rather than mechanical. 1 … 2 … [2]

6 marks

Mark scheme: 4(a)(i) Lever A is second order [1] 1 4(a)(ii) Tension 1 4(a)(iii) Counterweight B ensures that the lever arm returns to its resting position [1] when the tension in the cable is removed [1] 2 Allow marks for understanding shown. 4(b) Reasons could include: • More complex signals now required • Faster to change signal or modify function • No movement involved • Can be automated • Reduced maintenance 2 × 1 marks 2 Accept any other valid reason.

This question in 0445/43 Oct/Nov 2019

5 Fig. 2 shows two eccentrics on a locomotive axle. Fig. 2 (a) Give the conversion of motion produced by an eccentric. … to … [2] (b) Name one other mechanism that will produce the same conversion of motion. … [1]

3 marks

Mark scheme: 5(a) Rotary motion 1 mark to reciprocating motion 1 mark 2 5(b) • Crank and slider. • Cam and follower 1 Accept crankshaft Allow ecf from 5(b)

This question in 0445/43 Oct/Nov 2019

10 Fig. 8 shows an arrangement of gears driven by a small electric motor. C 60t B 16t E 60t A D 16t Fig. 8 (a) (i) State the name of gear A. … [1] (ii) Give two reasons for using this type of gear. 1 … 2 … [2] (iii) Gear B is an idler gear. Give two reasons for using an idler gear. 1 … 2 … [2] (iv) Calculate the gear ratio between the driver gear A and the driven gear E. … … … … [3] (v) The gears are all made from nylon. State two properties of nylon that make it suitable for use in small gear systems. 1 … 2 … [2] (b) Fig. 9 shows a chain and sprocket drive. Fig. 9 Use sketches and notes to show one method of adjusting the tension on the chain. [3] (c) Mechanisms can be powered in a number of ways. (i) State one safety precaution for each of the power sources given below. Electricity … Natural gas … Steam … Compressed air … [4] (ii) Describe the problems associated with the storage of electrical energy. … … … … [3] (iii) Explain how electronics and compressed air can be combined in a pneumatic system. … … … … [3] (d) Fig. 10 shows a gravity feed oil reservoir fitted on a steam engine. The lubricating oil in the reservoir falls onto the shaft and bearings below. oil reservoir bearings shaft Fig. 10 Give two drawbacks of a gravity feed oil reservoir. 1 … 2 … [2]

25 marks

Mark scheme: 10(a)(i) Gear A is a worm gear 1 10(a)(ii) Worm gears are used to: • Give large reduction of speed in a small space • Prevent reverse action / can only be turned in one direction • Transfer torque effectively 2 × 1 marks 2 10(a)(iii) An idler gear is used to: • Transfer drive from a driver gear to other gears in a train • Reverse the direction of motion without affecting speed of rotation • In a softer material as a sacrificial gear that can be easily replaced 2 × 1 marks 2 Allow ‘to provide space between other gears’ 10(a)(iv) Gear A to gear C is 60:1 reduction, 1 mark Gear D to gear E is 60 / 16:1 reduction = 3.75:1, 1 mark Final gear ratio is 60 × 3.75 = 225:1, 1 mark 3 10(a)(v) Properties of nylon include: • No lubrication required • Quiet in operation • Will resist chemicals • Can be moulded in one piece rather that teeth being cut individually 2 × 1 marks 2 Question Answer Marks Guidance 10(b) Tensioning can be achieved in two ways: • Moving the two gears further apart • Applying pressure to the chain with a pad or jockey wheel Valid principal used, 1 mark Clear sketches / notes, 1 mark Fixing methods / extra parts clearly shown / described, 1 mark 3 10(c)(i) Safety considerations could be: • Electricity – fuse / circuit breaker / insulation / earth system • Natural gas – pressure kept to a safe level, ensuring no leaks • Steam – boilers tested regularly, pipes checked for leaks, pressure regulator or safety valve • Compressed air – pressure reduced to a safe level, all components fixed down before testing a circuit 4 Allow any other safety precautions for each of the power sources. 10(c)(ii) Storage of electricity: • Currently only available in the form of batteries • Batteries can be bulky and costly • Safety considerations of batteries overheating and causing fires. • Not enough batteries are available for windy / sunny days when surplus electricity is produced 3 Explanation with three points, 3 marks Two points with no justification, 2 marks Allow 2 marks for a single point fully explained. Single point unjustified, 1 mark 10(c)(iii) Use of solenoid valves for switching and reed switch cylinders for sensing the position of pistons Computer systems / programmable logic units can control the pneumatic components 3 Principal shown, 1 mark Two items shown and clearly drawn / explained, 2 marks Allow 2 marks for clear drawing / notes on a single aspect. 10(d) Drawbacks of oil reservoir could be: • Needs regular filling • Time consuming • As bearings wear more oil is used • Oil is lost 2 × 1 marks 2

This question in 0445/43 Oct/Nov 2019

5 A spanner is an example of a second order lever. Draw a different example of a second order lever and show the position of the fulcrum, effort, and load. [4]

4 marks

Mark scheme: 5 Valid example of a second order lever, 1 mark. 1 mark each for fulcrum load 4 and effort correctly indicated. 4 × 1 mark

This question in 0445/41 May/June 2020

6 Spur gears can be used to transmit motion from one shaft to another. Draw an arrangement showing the minimum number of spur gears which will allow two shafts to rotate in the same direction. [2]

2 marks

Mark scheme: 6 Drawing to show three spur gears, the centre one an idler gear. 1 mark for 2 idler gear used, 1 mark for correct positioning of all three gears. 2 × 1

This question in 0445/41 May/June 2020

7 Fig. 7.1 shows two parts of a machine where movement takes place in the directions shown. Fig. 7.1 (a) Give one method of reducing friction between parts X and Y. … [1] (b) Name the type of motion indicated in Fig. 7.1. … [1]

2 marks

Mark scheme: 7(a) Lubrication, 1 mark 1 7(b) Reciprocating motion, 1 mark 1

This question in 0445/41 May/June 2020

11 (a) Fig. 11.1 shows three methods of transmitting motion from one shaft to another. R S T toothed belt vee belt flat belt Fig. 11.1 (i) Give one different reason for choosing each of the methods shown. R … S … T … [3] (ii) Use sketches and notes to show a method of tensioning the flat belt without moving either of the pulley shafts. [3] (b) Fig. 11.2 shows the chain drive on a cycle. rear sprockets chainring crank Fig. 11.2 (i) Give two factors that will affect the length of chain needed. 1 … 2 … [2] (ii) Fig. 11.3 shows a close-up view of a chain link. outer links inner links pin rollers inner link assembled inner link separated Fig. 11.3 State the type of bearing used in each link of the chain. … [1] (iii) Explain how the operating conditions for the cycle can affect the working life of the chain. … … … … [3] (iv) The cycle has wheels with a diameter of 700 mm, the front chainring has 51 teeth and the rear sprocket has 17 teeth. Calculate the distance travelled by the cycle during each revolution of the crank. Use the formula: circumference of wheel = 2 πr … … … … [3] (v) Give one reason for the drive system on a cycle not being 100% efficient. … [1] (c) Fig. 11.4 shows two methods that can be used to prevent reverse rotation in a mechanism. X Y Fig. 11.4 (i) Name each of the methods. X … Y … [2] (ii) Explain how each method can prevent reverse rotation. Method X … … … … Method Y … … … … [4] (d) Fig. 11.5 shows part of a steam engine. Z Fig. 11.5 (i) Name component Z. … [1] (ii) Describe the conversion of motion caused by component Z. … … … [2]

25 marks

Mark scheme: 11(a)(i) Reasons for using each type of belt will include: 3 • R toothed belt will not slip, pulleys are kept in the sae relative position to each other • S Vee belt will transmit torque better than other types • As belt moves down in the vee torque is transmitted through the sides of the belt • Standard sizes readily available. • T The flat belt is relatively low cost. • It can be twisted for reverse drive • A range of belt widths can be used on the same pulleys. 3 × 1 mark 11(a)(ii) Functional method of tensioning, 1 mark 3 Adjustment possible, 1 mark Clear description / sketches used to communicate idea. 11(b)(i) Two factors from: 2 • Largest chainring, 1 mark • Largest sprocket, 1 mark. • Length of derailleur cage • Length of chain stay. 2 × 1 mark 11(b)(ii) Plain bearing. 1 11(b)(iii) Points in explanation could be: 3 • If cycle is used in wet weather or snow lubrication can be washed off • Dry dusty weather will cause a build-up of dirt on the chain. This can be abrasive and cause wear in the chain and the sprockets. • The chain can rust if no lubrication is applied • Operating the gears with the chain at extremes e.g. large chainring, large sprocket can cause wear on chain 11(b)(iv) The gearing means that the rear wheel will rotate three times for each 3 revolution of the crank, 51/17 = 3, 1 mark Circumference of wheel = 2 × π × 350 = 2199 mm, 1 mark Distance travelled = 2199 × 3 = 6597.34 mm, 1 mark. 11(b)(v) Friction in moving parts will reduce efficiency. 1 Additional movement due to wear in bearings will reduce efficiency, 1 mark. 11(c)(i) X is a worm gear / worm and wheel, 1 mark 2 Y is a ratchet and pawl, 1 mark 11(c)(ii) Worm wheel: 4 Notes to show that a movement of the spur gear against the worm will cause a sideways movement of the worm, 1 mark, putting thrust on the side of the worm gear and not allowing any rotational movement, 1 mark. Ratchet and pawl: Notes to show that the pawl is held in place by a spring against the rachet, 1 mark, locking it in position to prevent reverse rotation, 1 mark. 11(d)(i) Component Z is a crankshaft, 1 mark. 1 11(d)(ii) Reciprocation motion in the piston is converted to rotary motion in the 2 crankshaft, 2 marks.

This question in 0445/41 May/June 2020

3 Fig. 3.1 shows a gate latch. Fig. 3.1 (a) State the order of lever used in the latch. … [1] (b) Draw a different example of where the order of lever shown in Fig. 3.1 is used. [2]

3 marks

Mark scheme: 3(a) Second order lever, 1 mark. 1 3(b) Suitable example, 1 mark. Clear drawing with E/L/F visible, 1 mark 2

This question in 0445/42 May/June 2020

4 (a) Give two reasons why spur gears are used to connect two shafts together. 1 … … 2 … … [2] (b) Fig. 4.1 shows a motor shaft and driven shaft which will be connected using spur gears. The direction of rotation of the motor shaft and driven shaft are shown. motor shaft driven shaft Fig. 4.1 Add the outline shape of spur gears that would reduce the speed of the driven shaft and produce the direction of rotation shown. [3]

5 marks

Mark scheme: 4(a) Reasons could be: 2 • Slipping not acceptable / positive drive • Change in relative speed required • Reduction in part count / no belt or chain required • Low cost of injection moulded gears 2 × 1 mark. 4(b) 3 motor shaft driven shaft 2 gears used, 1 mark. Small gear on motor, large on driven shaft, 1 mark. Gears shown correctly meshed, 1 mark.

This question in 0445/42 May/June 2020

11 (a) Fig. 11.1 shows two uses for bevel gears. driven bevel gear driver bevel gear handle 15t idler gear operating handle fixing point 56t gear 15t gear chuck Dockyard crane Hand drill Fig. 11.1 (i) Use the terms below to complete the description of what is happening in the two examples in Fig. 11.1. 90º 45º slower decrease faster increase 180º remain the same The driven gear in the hand drill will rotate … than the driving gear and the torque will … . The driven gear in the crane will rotate … than the driving gear and the torque will … . In both cases the drive will have moved through … . [5] (ii) Calculate the rotational speed of the handle on the hand drill if the chuck rotates at 475 rpm. … … … … [3] (iii) In both examples in Fig. 11.1 the operational conditions could affect the working life of the gears. Describe what could be done to overcome this problem. … … … … [2] (b) Fig. 11.2 shows a cam profile and follower. 15 25 Fig. 11.2 (i) State the conversion of motion that results from using a cam. … to … [2] (ii) Mark the direction of rotation of the cam on Fig. 11.2. [1] (iii) Give the vertical distance that the follower is lifted in each revolution of the cam in Fig. 11.2. … [1] (iv) Use sketches and notes to show the profile of a cam that will lift a follower twice for each revolution and will have no dwell. [2] (c) Fig. 11.3 shows a heavy packing crate. X edge X floor level 100 Fig. 11.3 Edge X of the packing crate needs to be lifted by 100 mm to the position shown. Draw a design on Fig. 11.3 for a lever system that will allow the edge to be lifted by 100 mm. [3] (d) Fig. 11.4 shows details of a screw thread that is used in a woodworking vice. 6 25 Fig. 11.4 (i) Calculate the mechanical advantage of the screw thread. circumference Use the formula: MA = pitch … … … [2] (ii) The end of the woodworking vice handle applies a load 16 times greater than the effort. Calculate the maximum force applied by the screw thread for an effort of 20 N at the end of the handle. … … [2] (iii) Explain why the actual load applied by the screw thread will be reduced. … … … [2]

25 marks

Mark scheme: 11(a)(i) The driven gear in the hand drill will rotate faster than the driving gear and 5 the torque will decrease. The driven gear in the crane will rotate slower than the driving gear and the torque will increase. In both cases the drive will have moved through 90º. 1 mark for each correct. 11(a)(ii) Gear ratio = 3.73 : 1 [1] 3 475 / 3.73, [1] = 127.3 rpm [1] 11(a)(iii) Lubrication, 1 mark 2 Covering / protecting the gears to prevent ingress of abrasive substances, 1 mark. 11(b)(i) Rotary motion to reciprocating motion, 1 mark for each. 2 11(b)(ii) 1 1 mark for anticlockwise rotation 11(b)(iii) 10 mm 1 11(b)(iv) 2 Two lifts on cam profile, 1 mark No dwell, 1 mark. 11(c) 3 Lever will fit under packing case, 1 mark Handle long enough to decrease effort needed, 1 mark Will provide 100mm lift when rotated, 1 mark 11(d)(i) Circumference = 3.14159 × 25 = 78.54 2 MA = 78.54 / 6 = 13.09 11(d)(ii) Total MA = 13.09 × 16 = 209.44, 1 mark 2 209.44 × 20 = 4189 N, 1 mark 11(d)(iii) Loss of efficiency, 1 mark due to friction between male and female thread, 2 1 mark.

This question in 0445/42 May/June 2020

5 A spanner is an example of a second order lever. Draw a different example of a second order lever and show the position of the fulcrum, effort, and load. [4]

4 marks

Mark scheme: 5 Valid example of a second order lever, 1 mark. 1 mark each for fulcrum load 4 and effort correctly indicated. 4 × 1 mark

This question in 0445/43 May/June 2020

6 Spur gears can be used to transmit motion from one shaft to another. Draw an arrangement showing the minimum number of spur gears which will allow two shafts to rotate in the same direction. [2]

2 marks

Mark scheme: 6 Drawing to show three spur gears, the centre one an idler gear. 1 mark for 2 idler gear used, 1 mark for correct positioning of all three gears. 2 × 1

This question in 0445/43 May/June 2020

7 Fig. 7.1 shows two parts of a machine where movement takes place in the directions shown. Fig. 7.1 (a) Give one method of reducing friction between parts X and Y. … [1] (b) Name the type of motion indicated in Fig. 7.1. … [1]

2 marks

Mark scheme: 7(a) Lubrication, 1 mark 1 7(b) Reciprocating motion, 1 mark 1

This question in 0445/43 May/June 2020

11 (a) Fig. 11.1 shows three methods of transmitting motion from one shaft to another. R S T toothed belt vee belt flat belt Fig. 11.1 (i) Give one different reason for choosing each of the methods shown. R … S … T … [3] (ii) Use sketches and notes to show a method of tensioning the flat belt without moving either of the pulley shafts. [3] (b) Fig. 11.2 shows the chain drive on a cycle. rear sprockets chainring crank Fig. 11.2 (i) Give two factors that will affect the length of chain needed. 1 … 2 … [2] (ii) Fig. 11.3 shows a close-up view of a chain link. outer links inner links pin rollers inner link assembled inner link separated Fig. 11.3 State the type of bearing used in each link of the chain. … [1] (iii) Explain how the operating conditions for the cycle can affect the working life of the chain. … … … … [3] (iv) The cycle has wheels with a diameter of 700 mm, the front chainring has 51 teeth and the rear sprocket has 17 teeth. Calculate the distance travelled by the cycle during each revolution of the crank. Use the formula: circumference of wheel = 2 πr … … … … [3] (v) Give one reason for the drive system on a cycle not being 100% efficient. … [1] (c) Fig. 11.4 shows two methods that can be used to prevent reverse rotation in a mechanism. X Y Fig. 11.4 (i) Name each of the methods. X … Y … [2] (ii) Explain how each method can prevent reverse rotation. Method X … … … … Method Y … … … … [4] (d) Fig. 11.5 shows part of a steam engine. Z Fig. 11.5 (i) Name component Z. … [1] (ii) Describe the conversion of motion caused by component Z. … … … [2]

25 marks

Mark scheme: 11(a)(i) Reasons for using each type of belt will include: 3 • R toothed belt will not slip, pulleys are kept in the sae relative position to each other • S Vee belt will transmit torque better than other types • As belt moves down in the vee torque is transmitted through the sides of the belt • Standard sizes readily available. • T The flat belt is relatively low cost. • It can be twisted for reverse drive • A range of belt widths can be used on the same pulleys. 3 × 1 mark 11(a)(ii) Functional method of tensioning, 1 mark 3 Adjustment possible, 1 mark Clear description / sketches used to communicate idea. 11(b)(i) Two factors from: 2 • Largest chainring, 1 mark • Largest sprocket, 1 mark. • Length of derailleur cage • Length of chain stay. 2 × 1 mark 11(b)(ii) Plain bearing. 1 11(b)(iii) Points in explanation could be: 3 • If cycle is used in wet weather or snow lubrication can be washed off • Dry dusty weather will cause a build-up of dirt on the chain. This can be abrasive and cause wear in the chain and the sprockets. • The chain can rust if no lubrication is applied • Operating the gears with the chain at extremes e.g. large chainring, large sprocket can cause wear on chain 11(b)(iv) The gearing means that the rear wheel will rotate three times for each 3 revolution of the crank, 51/17 = 3, 1 mark Circumference of wheel = 2 × π × 350 = 2199 mm, 1 mark Distance travelled = 2199 × 3 = 6597.34 mm, 1 mark. 11(b)(v) Friction in moving parts will reduce efficiency. 1 Additional movement due to wear in bearings will reduce efficiency, 1 mark. 11(c)(i) X is a worm gear / worm and wheel, 1 mark 2 Y is a ratchet and pawl, 1 mark 11(c)(ii) Worm wheel: 4 Notes to show that a movement of the spur gear against the worm will cause a sideways movement of the worm, 1 mark, putting thrust on the side of the worm gear and not allowing any rotational movement, 1 mark. Ratchet and pawl: Notes to show that the pawl is held in place by a spring against the rachet, 1 mark, locking it in position to prevent reverse rotation, 1 mark. 11(d)(i) Component Z is a crankshaft, 1 mark. 1 11(d)(ii) Reciprocation motion in the piston is converted to rotary motion in the 2 crankshaft, 2 marks.

This question in 0445/43 May/June 2020

4 Fig. 4.1 shows details of a self-grip wrench being locked onto a nut between the jaws. The lower jaw is acting as a lever, locking onto the nut when pressure is applied. lock being applied locked outline of lower jaw lower jaw Fig. 4.1 (a) Add the letters E, F and L to three of the circles in Fig. 4.1 to show the position of the effort, fulcrum and load in the lever. [3] (b) State the order of lever used in the lower jaw of the wrench. … [1]

4 marks

Mark scheme: 4(a) 1 mark for each correct label. 3 No mark for the same letter being used twice. 4(b) 1st order or class 1 lever, 1 mark 1

This question in 0445/42 Oct/Nov 2020

5 State the type of motion which occurs in the following examples. Clock pendulum … Cutting with a hacksaw … [2]

2 marks

Mark scheme: 5 Clock pendulum – oscillating motion, 1 mark. Cutting with a saw – reciprocating motion, 1 mark. 2

This question in 0445/42 Oct/Nov 2020

6 Give two reasons for using spur gears to transmit motion in a mechanism. 1 … … 2 … … [2]

2 marks

Mark scheme: 6 Reasons for using spur gears could be: • To connect two shafts together • Increase or decrease speed of output shaft • Avoid any chance of slippage / positive drive • Increase torque in output shaft • Change direction of motion. 2 × 1 marks 2 Allow any other valid alternative.

This question in 0445/42 Oct/Nov 2020

10 Fig. 10.1 shows a toy steam locomotive. X W Fig. 10.1 (a) (i) Circle from the list below the mechanism that is formed by parts W and X. rack and pinion crank and slider worm and wheel belt and pulley ratchet and pawl [1] (ii) Give the conversion of motion produced by this mechanism. … to … [2] (iii) Fig. 10.2 shows the base of the toy steam locomotive. cam follower in high and low positions follower cam fixed to rear wheel axle Fig. 10.2 The cam and follower are used to produce a sound in the toy. State the number of times that the follower will be lifted for each rotation of the cam. … [1] (iv) The cam and follower are both made from nylon. Give two benefits of using nylon to make the parts. 1 … 2 … [2] (b) Fig. 10.3 shows bearings that can be found in a mechanism. direction of radial load roller bearing ball bearing Fig. 10.3 (i) Explain why the roller bearing can withstand greater radial load than the ball bearing. … … … [2] (ii) Give one reason for a bearing failing in a mechanism. … … [1] (c) Fig. 10.4 shows a compound gear system. The 18t and 60t gear in B are fixed together and the 15t and 60t gear in C are fixed together. 18t 15t 75t 60t 60t B C D A Fig. 10.4 (i) Mark the direction of rotation on the 75t gear. [1] (ii) Give two reasons for using a worm gear in a mechanical system. 1 … 2 … [2] (iii) Calculate the velocity ratio for each stage in the system and complete Table 10.1. … … … … Table 10.1 stage velocity ratio A to B B to C C to D A to D [4] (d) (i) Compare the following methods of transmitting motion. Give one advantage and one disadvantage for each method. Chain drive Advantage … Disadvantage … Pulley and round belt Advantage … Disadvantage … Pulley and toothed belt Advantage … Disadvantage … [6] (ii) Use sketches and notes to show one method of tensioning a drive belt. [3]

25 marks

Mark scheme: 10(a)(i) Circle around ‘Crank and Slider’, 1 mark. 1 10(a)(ii) Rotary [1] to Reciprocating, 1 mark. 2 10(a)(iii) 2 1 Question Answer Marks Guidance 10(a)(iv) Benefits could include: • Self-lubricating • Low cost • Can be injection moulded / fast production • Will not get damaged easily. 2 × 1 marks 2 Allow other valid alternatives. 10(b)(i) Points in explanation could include: • The roller bearing has a greater contact area than a ball bearing • Rollers are normally larger diameter than a ball • Pitting in the surface of a roller is not so likely to affect performance • Roller is not so likely to be resisting axial loading at the same time. 2 Two points included, 2 marks Allow 2 marks for one point fully explained. 10(b)(ii) Bearing failure can be attributed to: • Lack of lubrication • Ingress of dirt / abrasive substances / water • Excessive heat causes surface of bearing to melt. 1 Allow other valid alternatives 10(c)(i) The 75t gear rotates anticlockwise. 1 10(c)(ii) Reasons for using a worm gear will include: • Cannot be turned backwards / shaft is self-locking • High transfer of torque • More compact than spur gears • Large reduction in speed possible 2 × 1 marks. 2 Question Answer Marks Guidance 10(c)(iii) stage velocity ratio A to B 60 : 1 B to C 3.33 : 1 C to D 5 : 1 A to D 60 × 3.33 × 5 = 1000 : 1 4 Allow 10 : 3 for B to C. 10(d)(i) Chain drive Advantage – little chance of breaking Disadvantage – can be noisy, 2 × 1 marks Pulley and round belt Advantage – low cost / belt easily replaced Disadvantage – belt can slip or break, 2 × 1 marks Pulley and toothed belt Advantage – cannot slip / relative position on pulley remains the same Disadvantage – regular replacement needed / belt can stretch, 2 × 1 marks. 6 Allow any other valid alternatives. 10(d)(ii) Either a tensioner pressed against the belt, sprung loaded or gravity or method of moving one of the pulleys / slotted fixing. • Functional method, 1 mark • Details of how adjustment is carried out, 1 mark • Clear sketches / notes, 1 mark. 3

This question in 0445/42 Oct/Nov 2020

4 Fig. 4.1 shows details of a self-grip wrench being locked onto a nut between the jaws. The lower jaw is acting as a lever, locking onto the nut when pressure is applied. lock being applied locked outline of lower jaw lower jaw Fig. 4.1 (a) Add the letters E, F and L to three of the circles in Fig. 4.1 to show the position of the effort, fulcrum and load in the lever. [3] (b) State the order of lever used in the lower jaw of the wrench. … [1]

4 marks

Mark scheme: 4(a) 1 mark for each correct label. 3 No mark for the same letter being used twice. 4(b) 1st order or class 1 lever, 1 mark 1

This question in 0445/43 Oct/Nov 2020

5 State the type of motion which occurs in the following examples. Clock pendulum … Cutting with a hacksaw … [2]

2 marks

Mark scheme: 5 Clock pendulum – oscillating motion, 1 mark. Cutting with a saw – reciprocating motion, 1 mark. 2

This question in 0445/43 Oct/Nov 2020

6 Give two reasons for using spur gears to transmit motion in a mechanism. 1 … … 2 … … [2]

2 marks

Mark scheme: 6 Reasons for using spur gears could be: • To connect two shafts together • Increase or decrease speed of output shaft • Avoid any chance of slippage / positive drive • Increase torque in output shaft • Change direction of motion. 2 × 1 marks 2 Allow any other valid alternative.

This question in 0445/43 Oct/Nov 2020

10 Fig. 10.1 shows a toy steam locomotive. X W Fig. 10.1 (a) (i) Circle from the list below the mechanism that is formed by parts W and X. rack and pinion crank and slider worm and wheel belt and pulley ratchet and pawl [1] (ii) Give the conversion of motion produced by this mechanism. … to … [2] (iii) Fig. 10.2 shows the base of the toy steam locomotive. cam follower in high and low positions follower cam fixed to rear wheel axle Fig. 10.2 The cam and follower are used to produce a sound in the toy. State the number of times that the follower will be lifted for each rotation of the cam. … [1] (iv) The cam and follower are both made from nylon. Give two benefits of using nylon to make the parts. 1 … 2 … [2] (b) Fig. 10.3 shows bearings that can be found in a mechanism. direction of radial load roller bearing ball bearing Fig. 10.3 (i) Explain why the roller bearing can withstand greater radial load than the ball bearing. … … … [2] (ii) Give one reason for a bearing failing in a mechanism. … … [1] (c) Fig. 10.4 shows a compound gear system. The 18t and 60t gear in B are fixed together and the 15t and 60t gear in C are fixed together. 18t 15t 75t 60t 60t B C D A Fig. 10.4 (i) Mark the direction of rotation on the 75t gear. [1] (ii) Give two reasons for using a worm gear in a mechanical system. 1 … 2 … [2] (iii) Calculate the velocity ratio for each stage in the system and complete Table 10.1. … … … … Table 10.1 stage velocity ratio A to B B to C C to D A to D [4] (d) (i) Compare the following methods of transmitting motion. Give one advantage and one disadvantage for each method. Chain drive Advantage … Disadvantage … Pulley and round belt Advantage … Disadvantage … Pulley and toothed belt Advantage … Disadvantage … [6] (ii) Use sketches and notes to show one method of tensioning a drive belt. [3]

25 marks

Mark scheme: 10(a)(i) Circle around ‘Crank and Slider’, 1 mark. 1 10(a)(ii) Rotary [1] to Reciprocating, 1 mark. 2 10(a)(iii) 2 1 Question Answer Marks Guidance 10(a)(iv) Benefits could include: • Self-lubricating • Low cost • Can be injection moulded / fast production • Will not get damaged easily. 2 × 1 marks 2 Allow other valid alternatives. 10(b)(i) Points in explanation could include: • The roller bearing has a greater contact area than a ball bearing • Rollers are normally larger diameter than a ball • Pitting in the surface of a roller is not so likely to affect performance • Roller is not so likely to be resisting axial loading at the same time. 2 Two points included, 2 marks Allow 2 marks for one point fully explained. 10(b)(ii) Bearing failure can be attributed to: • Lack of lubrication • Ingress of dirt / abrasive substances / water • Excessive heat causes surface of bearing to melt. 1 Allow other valid alternatives 10(c)(i) The 75t gear rotates anticlockwise. 1 10(c)(ii) Reasons for using a worm gear will include: • Cannot be turned backwards / shaft is self-locking • High transfer of torque • More compact than spur gears • Large reduction in speed possible 2 × 1 marks. 2 Question Answer Marks Guidance 10(c)(iii) stage velocity ratio A to B 60 : 1 B to C 3.33 : 1 C to D 5 : 1 A to D 60 × 3.33 × 5 = 1000 : 1 4 Allow 10 : 3 for B to C. 10(d)(i) Chain drive Advantage – little chance of breaking Disadvantage – can be noisy, 2 × 1 marks Pulley and round belt Advantage – low cost / belt easily replaced Disadvantage – belt can slip or break, 2 × 1 marks Pulley and toothed belt Advantage – cannot slip / relative position on pulley remains the same Disadvantage – regular replacement needed / belt can stretch, 2 × 1 marks. 6 Allow any other valid alternatives. 10(d)(ii) Either a tensioner pressed against the belt, sprung loaded or gravity or method of moving one of the pulleys / slotted fixing. • Functional method, 1 mark • Details of how adjustment is carried out, 1 mark • Clear sketches / notes, 1 mark. 3

This question in 0445/43 Oct/Nov 2020

4 Fig. 4.1 shows a door handle and latch. door handle latch Fig. 4.1 (a) State the conversion of motion that takes place between the door handle and latch. … to … [2] (b) Give one example of a mechanism that gives a different conversion of motion. Name of mechanism … Conversion of motion … to … [2]

4 marks

Mark scheme: 4(a) Oscillating (door handle) to reciprocating (latch), 1 mark for each correctly identified motion. 2 Question Answer Marks Guidance 4(b) Input motion identified 1 mark. Output motion identified, 1 mark. 2 No marks for name of mechanism Conversion must match mechanism.

This question in 0445/42 May/June 2021

5 Fig. 5.1 shows a series of spur gears in a machine. input shaft output shaft 45t 45t 15t Fig. 5.1 (a) Give two reasons for using the spur gears in this arrangement. 1 … 2 … [2] (b) Describe the result of using a 15t spur gear on an input shaft and using a 45t spur gear on an output shaft. … … … … [2]

4 marks

Mark scheme: 5(a) • Output will rotate in the same direction as input, 1 mark • To connect two fixed shafts which are located apart from each other. • Idler gear could be a sacrificial gear to protect the input/output gears. • So that the drive does not slip • Speed of both shafts is the same. 2 × 1 marks. 2 Allow any other valid response. 5(b) Speed of rotation of the output gear will be reduced, 1 mark Direction of rotation changed, 1 mark Torque of output gear will increase, 1 mark. 2 × 1 marks 2

This question in 0445/42 May/June 2021

7 Give one reason why lubrication is important in mechanisms. … … [1]

1 marks

Mark scheme: 7 Lubrication is used to: • Reduce friction • Reduce wear in moving parts • Provide a cooling effect on moving parts • Reduces sound • To carry away any small particles of material that could damage bearing surfaces in the mechanism.

This question in 0445/42 May/June 2021

11 (a) Fig. 11.1 shows a belt and pulley system. output pulley Ø400 input pulley Ø300 Fig. 11.1 (i) Give two changes in movement of the output pulley compared to movement of the input pulley. 1 … 2 … [2] (ii) Fig. 11.2 shows three spur gears. Ø200 Ø150 Ø50 Fig. 11.2 Draw the outline of two of the spur gears arranged to give the same change to the output as the belt and pulley system in Fig. 11.1. Label the input and output. [3] (iii) Give two benefits and two drawbacks that spur gears have when compared to a belt and pulley system. Benefits 1 … … 2 … … Drawbacks 1 … … 2 … … [4] (iv) Fig. 11.3 shows a compound gear arrangement from input gear A to output gear D. 60t 75t 75t A B C D 15t 15t 18t Fig. 11.3 Calculate the velocity ratio of the system. … … … … [4] (v) Indicate on Fig. 11.3 the direction of rotation of input gear A. [1] (b) Fig. 11.4 shows a steam locomotive with an enlarged view of the driving wheels. piston rod C wheel A wheel B Fig. 11.4 Use words from the list below to complete the sentences describing the drive system. Each word may be used once, more than once or not at all. linear linkage reciprocating slider oscillating crank rotary rack The piston rod connects to wheel A through a … and … mechanism. The … motion of the piston rod is converted to … motion at wheel A. Part C is a … that connects wheel A to wheel B. [5] (c) Fig. 11.5 shows a shaft in a machine supported by plain bearings. plain bearings Fig. 11.5 (i) Explain why bearings are needed to support a shaft in a machine. … … … [2] (ii) Give two features of a plain bearing. 1 … … 2 … … [2] (iii) Name two other types of bearing that could be used to support a shaft. 1 … 2 … [2]

25 marks

Mark scheme: 11(a)(i) The output pulley will rotate slower than the input pulley, 1 mark. The output pulley will rotate in the opposite direction to the input pulley, 1 mark. 2 11(a)(ii) Correct choice of gears, 1 mark Positioning of gears, 1 mark Labelling of gears, 1 mark. 3 11(a)(iii) Benefits of spur gears could be: • No chance of slipping • Good transfer of torque • No belt to break 2 × 1 marks Drawbacks could be: • Precise positioning of gears needed • More expensive than a belt and pulley system • Can jam, causing breakage of teeth 2 × 1 marks. 4 Allow any other valid benefits or drawbacks. 11(a)(iv) Ratio from A to B is 60 / 15 = 4 : 1 Ratio from B to C is 75 / 18 = 4.2 : 1 Ratio from C to D is 75 / 15 = 5 : 1 Ratio from a to D is 4 x 4.2 x 5 = 84 : 1 1 mark for each line correct, 4 × 1 marks. 4 Award 4 marks for an answer of 84:1 with no intermediate values given. 11(a)(v) Gear A will turn clockwise, 1 mark. 1 Ø150 Ø200 driver driven Question Answer Marks Guidance 11(b) A crank and slider mechanism connects the piston rod to wheel A. The reciprocating motion of the piston rod is converted to rotary motion at wheel A. Part C is a linkage that connects wheel A to wheel B. 1 mark for each word in the correct position, 5 × 1 marks. 5 Accept slider and crank. 11(c)(i) Reasons for using bearings could include: • To reduce friction in the moving parts • To allow for a film of oil / grease to separate the surfaces of mating parts • To prevent wear in the shaft • To prevent wear in body of machine • Bearings allow for replacement when worn. 2 Allow other valid points 2 marks for two points mentioned 2 marks for one point described in depth. 11(c)(ii) Features of a plain bearing could include: • No moving parts • Normally a softer material than the shaft or body of machine • Can be porous to allow oil to be absorbed. • Can be split to allow for fitting 2 × 1 marks. 2 Allow other valid features. 11(c)(iii) Other types of bearing include: • Ball • Roller • Tapered roller • Needle 2 × 1 marks. 2

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3 Fig. 3.1 shows salad tongs, which are an example of a third order lever. Fig. 3.1 (a) Add the positions of the fulcrum, effort and load to Fig. 3.1. [3] (b) Explain how a third order lever is different to first and second order levers. … … … [2]

5 marks

Mark scheme: 3(a) 1 mark for each correct. twice, 3(b) • A third order lever is the only one that cannot give a mechanical advantage, [1] • Effort is between the fulcrum and load, [1] • Increases precision in use. [1] 2 × 1 mark 2

This question in 0445/43 May/June 2021

4 Spur gears can be made from brass, nylon or steel. (a) Give one different reason for choosing each of these materials. Brass … Nylon … Steel … [3] (b) Name the applied load that could cause teeth on a spur gear to break off. … [1]

4 marks

Mark scheme: 4(a) Reasons for using materials will include: Brass • Will not corrode • Good bearing qualities • Teeth can be cut accurately Nylon • Low cost • Can be injection moulded rather than cut • No lubrication needed/low coefficient of friction • Can be used as ‘sacrificial’ gear Steel • Hard wearing / durable • Lower cost than brass • Readily available 3 × 1 mark Allow brass as self-lubricating. Allow durable only if it is not used for steel. Allow reference to the strength of steel. Question Answer Marks Guidance 4(b) Shear, 1 mark. 1

This question in 0445/43 May/June 2021

11 (a) (i) Use sketches and notes to show the meaning of the term ‘dwell’ in a cam. [2] (ii) Fig. 11.1 shows the profile of a cam and a follower. roller follower cam Fig. 11.1 Describe the movement of the follower for one rotation of the cam. … … … [2] (iii) Give one benefit of using a roller follower for this cam. … … [1] (b) Fig. 11.2 shows a ratchet and pawl mechanism used to tension a fence wire. fence wire tapered square head Fig. 11.2 (i) Explain how a ratchet and pawl mechanism operates. … … … … [3] (ii) Use sketches and notes to show a design for a tool suitable for turning the tapered square head on the mechanism. [3] (iii) Give one possible reason for the taper on the square head. … … [1] (iv) Describe how the tension in the fence wire can be released. … … … [2] (c) Fig 11.3 shows a compound pulley system that transfers drive from an electric motor to a small lathe. The system uses two belts. Ø22 motor Ø66 backplate Ø22 lathe Ø66 Fig. 11.3 (i) Calculate the output speed to the lathe with the belts in the position shown. The motor is turning at 1215 rpm. … … … … [3] (ii) Fig. 11.4 shows how the motor is mounted onto the backplate. backplate motor mounting motor shaft bolts Fig. 11.4 Give one reason why slots are used instead of round holes to mount the motor. … … … [1] (d) Fig 11.5 shows a drill chuck and chuck key. Fig. 11.5 (i) State the type of gear that is used between the drill chuck and chuck key. … [1] (ii) Describe the two features in Fig. 11.5 that together provide the mechanical advantage of the chuck key. 1 … … 2 … … [4] (iii) The axes of the chuck and chuck key are at 90° to each other. A worm gear is another type of gear that will connect axes at 90° to each other. Give two reasons for using a worm gear in a mechanism. 1 … … 2 … … [2]

25 marks

Mark scheme: 11(a)(i) Drawing of a cam with dwell clearly shown, 1 mark Label to indicate position of dwell, 1 mark. 2 11(a)(ii) • The follower will rise four times, 1 mark • The follower will fall four times, 1 mark • The rise and fall are the same distance each time, 1 mark • Mention of reciprocating motion, 1 mark • There is no dwell, 1 mark. 2 × 1 marks 2 Any two points included for 2 marks. 11(a)(iii) • The roller can follow the complete profile of the cam • Roller follower will reduce friction between cam and follower • A flat ended follower may bridge each of the lowest points 1 mark for suitable benefit. 1 Allow any other valid response 11(b)(i) Explanation should include: • It is a one-way mechanism • Pawl will drop into place through gravity or spring action • The pawl prevents reverse movement of the ratchet. 3 Two points mentioned for 2 marks. Allow 2 marks for a single point fully explained. No mark for ‘can apply tension’. 11(b)(ii) • Suitable size of tool / length of lever shown to give MA • Suitable width of lever in comparison to square head. • Square hole in one end of lever 3 Question Answer Marks Guidance 11(b)(iii) Reasons could be: • To allow ease of fitting lever to square head • Taper will hold lever in place securely and allow for easy removal. 1 Allow other valid reasons 11(b)(iv) The tension is increased slightly to allow free movement of the pawl, 1 mark Pawl is then lifted to allow shaft to rotate and fence wire to unwind, 1 mark 2 11(c)(i) Each pair of pulleys gives a reduction of 3 : 1 (66 / 22), 1 mark Total reduction is 3 × 3 = 9 : 1, 1 mark Lathe output speed = 1215 / 9 = 135 rpm, 1 mark 3 11(c)(ii) • The slots allow motor to be fitted/fixed in a suitable position • The belt from intermediate shaft to lathe pulley can be tensioned 1 mark for suitable reason. 1 11(d)(i) Bevel gear, 1 mark. 1 11(d)(ii) Features are: • The lever action of the chuck key / first order lever • The mechanical advantage of the bevel gears / driver smaller than driven 4 1 mark each for features, 1 mark each for description of how the feature increases MA. 11(d)(iii) Large reduction in speed, 1 mark More compact than other gear types, 1 mark One-way action, no reverse, 1 mark 2

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4 Fig. 4.1 shows a parcel tape dispenser. tape Fig. 4.1 Describe the conversion of motion that takes place when the tape is pulled out. … to … [2]

2 marks

Mark scheme: 4 Linear to rotary, 2 × 1 marks. 2 Allow 1 BOD mark for rotary to linear

This question in 0445/42 Oct/Nov 2021

5 (a) Give two reasons why a mechanism may require lubrication. 1 … 2 … [2] (b) Name two types of lubrication suitable for use in a mechanism. 1 … 2 … [2]

4 marks

Mark scheme: 5(a) Reasons for lubrication could include: • To reduce friction • To prevent corrosion • To prevent wear • To cool • Reduce noise • Allow parts to move easier. 2 × 1 marks 2 Allow other valid reasons. 5(b) Oil, grease, graphite, silicone, 2 × 1 marks. 2 Accept trade names. Allow other valid responses.

This question in 0445/42 Oct/Nov 2021

6 Use sketches and notes to show an example of a second order lever. [2]

2 marks

Mark scheme: 6 Valid example of a second order lever, 1 mark label / notes on at least one feature, 1 mark. 2

This question in 0445/42 Oct/Nov 2021

9 (a) Fig. 9.1 shows part of a plastic case to hold a circuit board. Y X 90 55 Fig. 9.1 (i) Draw a rib in the case between points X and Y. [2] (ii) Add four gussets to the round pillar. [2] (iii) Describe the purpose of the rib and gussets. … … … [2] (iv) Give two reasons why the designer of the casing should consider disassembly of the product. 1 … … 2 … … [2] (b) Fig. 9.2 shows two steel tubes each 2 m long which need to be joined end-to-end. (i) Use sketches and notes to show one permanent method of joining the tubes. Give details of any additional materials used. steel tube 20 × 20 × 2 Fig. 9.2 [3] (ii) Use sketches and notes to show one temporary method of joining the tubes. Give details of any additional materials or components used. [3] (c) Fig. 9.3 shows details of a tower crane in equilibrium, which is carrying a load of 5500 N. Two counterweights A and B each producing a force of 6200 N are used to balance the load. 6 m 3.6 m X A B 5500 N Fig. 9.3 (i) The crane is in a state of equilibrium. Give the meaning of equilibrium. … [1] (ii) Calculate distance X to the centre of counterweight A. … … … … [4] (iii) Give one static load and one moving load that the crane must resist. Static load … Moving load … [2] (iv) The tower crane is designed as a number of prefabricated parts that are bolted together. Give one reason for this method of construction. … … [1] (v) Explain the importance of ‘Factor of Safety’ in crane design. … … … … [3]

25 marks

Mark scheme: 9(a)(i) Rib in correct position, 1 mark. Functional shape, 1 mark. 2 9(a)(ii) Triangular gussets supporting pillar, 1 mark. Four gussets spaced around the pillar, 1 mark. 2 Accept 3 or more gussets. 9(a)(iii) • The rib and gussets are to provide support / reinforcement, 1 mark. • To add strength at a given point without significant increase in weight, 1 mark. • To prevent distortion 2 Allow marks for understanding shown. 9(a)(iv) Reasons for consideration of disassembly could be: • Ease of access for repair • Recycling of usable part in the circuit • Removal of parts to allow for recycling / disposal of case. 2 × 1 marks 2 Allow other valid reasons. Question Answer Marks Guidance 9(b)(i) Support either inside or outside of tubes, 1 mark. Indication of methods – welding / brazing, pop rivets, 1 mark. Permanent, functional method, 1 mark. 3 9(b)(ii) Support either inside or outside of tubes, 1mark. Indication of methods – bolts / screws / dowel pins, 1 mark. Temporary functional method, 1 mark. 3 9(c)(i) Definition of equilibrium – balanced, stable, all opposing forces are balanced, 1 mark. 1 Award mark for understanding shown. 9(c)(ii) 5500 × 6 = (X × 6200) + (3.6 × 6200), 1 mark 33 000 = (6200 X ) + 22 320, 1 mark 6200 X = 33 000 – 22 320 = 10 680, 1 mark X = 10 680 / 6200 = 1.7226 m, 1 mark 4 Award 4 marks for correct answer with no working. Question Answer Marks Guidance 9(c)(iii) Static load is: • Load from any of the crane components • Counterweights Moving load is: • Wind, snow, any other weather related condition • Load from items being lifted • Torque caused by rotation of the tower • Movement / swinging of the load being lifted 2 × 1 marks 1 mark for each 2 9(c)(iv) Reason for prefabrication will include: • Can be constructed and then moved to site • Ease of storage • Ease of transport • Crane structure is temporary. 1 mark. 1 Do not allow cost related reason. Allow other valid reasons. 9(c)(v) Points in explanation could include: • Unknown loads and conditions of use • Designer must consider all who will be working on the crane or in the area • Unknown stability of foundations where the base will rest. • Compliance with safety legislation. 3 1 mark for each point mentioned. Allow 2 marks for a fully justified point.

This question in 0445/42 Oct/Nov 2021

10 (a) Fig. 10.1 shows details of a cam operated clamp that is locked in place by a lever. open position closed position Fig. 10.1 (i) Mark the position of the fulcrum on the lever by adding the letter F in the correct circle. [1] (ii) Name the order of lever used. … [1] (iii) Fig. 10.2 shows details of the lever. 68 12 Fig. 10.2 Calculate the mechanical advantage given by the lever. … … … [2] (iv) Give two advantages of using a cam operated clamp rather than a screw operated clamp. 1 … … 2 … … [2] (b) Fig. 10.3 shows a socket wrench with a ratchet and pawl drive. square drives for pawl disengaged sockets reversing lever ratchet pawl engaged Fig. 10.3 (i) Describe the benefits of using a ratchet and pawl drive for a socket wrench. … … … [2] (ii) Explain the purpose of the reversing lever in the socket wrench. … … … … [3] (iii) Use sketches and notes to show one different use of a ratchet and pawl mechanism. [2] (c) Fig. 10.4 shows a pulley system used for lifting heavy loads. Fig. 10.4 (i) Describe how the velocity ratio of a pulley system can be determined. … … … … [2] (ii) Calculate the length of rope that must be pulled through the system to raise the load by 100 mm. … … … [2] (iii) Explain why the pulley system in Fig. 10.4 will not be 100% efficient. … … … [2] (d) Fig. 10.5 shows a range of spur gears. One gear of each size is available. 18 t 20 t 30 t 35 t 40 t 50 t Fig. 10.5 Choose gears from the range and draw them in a position that will cause the driven shaft to rotate at twice the speed of the driver shaft and in the same direction as the driver shaft. Label the driver gear and the number of teeth on all of the gears used. [3] (e) Fig. 10.6 shows the cross slide of a small lathe. The moving portion is held in place in a dovetail slot. A strip of nylon on one side has M4 adjustment screws to hold it in place. 50 M4 screws dovetail slot nylon strip 50 × 8 × 3 Fig. 10.6 (i) From the list below circle the type of bearing used between the moving parts. ball needle taper plain roller … [1] (ii) Give two reasons why nylon has been chosen for the adjustment strip. 1 … … 2 … … [2]

25 marks

Mark scheme: 10(a)(i) 1 mark for fulcrum in correct position. 10(a)(ii) Second order lever, 1 mark. 1 10(a)(iii) Mechanical advantage = length of effort arm / length of load arm = 68 / 12, 1 mark = 5.67, 1 mark 2 Award full marks for correct answer with no working. Allow 5.66 10(a)(iv) Advantages of a cam operated clamp will include: • Speed of operation • Suitable for repeated operations • Consistent pressure applied each time it is used • Takes up a small amount of space. 2 × 1 marks for suitable advantages. 2 Allow any other valid advantages. Allow ‘easier to use’ 10(b)(i) Benefits of a ratchet and pawl drive will include: • No need to remove the wrench from a nut to change position • Wrench does not have to turn through a large angle • Will only move in one direction / will not slip • Can be used in restricted space • Direction of drive can be reversed. 2 × 1 marks for suitable benefits. 2 Allow any other valid benefits. Question Answer Marks Guidance 10(b)(ii) The reversing lever will change direction of the drive allowing a nut to be undone as well as done up, [1] The lever moves the position of the pawls so that the one in contact with the ratchet can be disengaged and the opposite one is engaged, [1] Single handed operation is possible [1]. 3 Explanation that includes two valid points, 2 marks. Allow 2 marks for a well justified explanation of a single point. 10(b)(iii) Clear sketch, 1 mark. Valid use of ratchet and pawl, 1 mark. Examples could be screwdriver, screw jack, winch or any device where slipping back is not desirable. 2 10(c)(i) Description could include: The velocity ratio refers to: • the speed with which the rope is pulled compared to the speed of the load being raised, [1] • It relates directly to the mechanical advantage of the system, [1]. • Distance moved by effort Distance moved by load [1] 2 × 1 marks 2 Allow marks for understanding shown. 10(c)(ii) The system in Fig. 10.4 has a velocity ratio of 4:1 / MA of 4, 1 mark Length of pulled rope = 4 × 100 = 400 mm, 1 mark 2 10(c)(iii) The efficiency of a pulley system is decreased due to friction in the pulley bearings, 1 mark and the friction of the ropes against the pulley wheels, 1 mark. 2 Allow mark for results of friction – heat/sound 10(d) Driver pulley will be 40t, 1 mark. Driven pulley 20t, 1 mark. Any of the remaining pulleys can be used as an idler to change the direction of driven to match that of driver, 1 mark. 3 10(e)(i) The bearing used is a plain bearing, 1 mark. 1 Question Answer Marks Guidance 10(e)(ii) Reasons for using nylon will include: • It does not need regular lubrication • Nylon is a relatively soft material which can carry any debris / waste material without damaging the dovetail slot • Nylon can be compressed slightly so adjustment of the bearing is not so critical • Nylon is a low cost material. • Can resist a high load without deforming 2 × 1 marks for suitable reasons. 2

This question in 0445/42 Oct/Nov 2021

4 State two purposes of oil in a car engine. 1 … 2 … [2]

2 marks

Mark scheme: 4 Oil is used in a car engine to:  Lubricate the moving parts  Reduce friction  Prevent metal to metal contact  Remove grit / metal fragments from the moving parts  Assist with cooling of the engine. 2  1 marks.

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5 Fig. 5.1 shows two examples of conversion of motion. … … follower to to … … pencil sharpener pencil cam Fig. 5.1 For each example complete the labels in Fig. 5.1 to show the conversion of motion. [4]

4 marks

Mark scheme: 5 1 mark for each correct label, 4  1 marks. 4

This question in 0445/41 May/June 2022

10 Fig. 10.1 shows views of a wooden aircraft propeller made from a number of layers of hardwood glued together. Fig. 10.1 (a) (i) Name the method of construction that has been used to produce the propeller. … [1] (ii) Describe the properties that are required in the adhesive that is used to glue the hardwood layers together. … … … [2] (iii) Give two benefits to the manufacturer of using this method of construction to produce the propeller. 1 … … 2 … … [2] (b) Fig. 10.2 shows three methods of extending the length of a piece of steel tube. W X Y Fig. 10.2 (i) Complete Table 10.1 by adding ticks (3), to show two forces that, when applied to the extended length of tube, will be best resisted by each method. Table 10.1 Method Bending Torsion Compression Tension W X Y [6] (ii) For one of the methods used in part (b)(i), use sketches and notes to show an improvement that will allow it to resist greater force. Identify the greater forces being resisted. [3] (c) Fig. 10.3 shows two views of a wall bracket to hold a hanging basket for flowers. A B Fig. 10.3 (i) On view A draw a tie on the bracket to prevent the arm from bending. [2] (ii) On view B draw a strut that will prevent the arm from bending. [2] (iii) Add a gusset plate to view B to increase resistance to bending. [2] (d) Fig. 10.4 shows a car park barrier that can be raised or lowered by an electric motor to allow cars through. 3 m 0.8 m limit stop X 245 N Fig. 10.4 (i) Explain why a limit stop is used on the barrier. … … … … [2] (ii) Calculate the force required at point X needed to keep the barrier in equilibrium. … … … … [3]

25 marks

Mark scheme: 10(a)(i) Lamination is the method of construction 1 10(a)(ii) Properties of adhesive could include:  Must be waterproof / water resistant  Gap filling  Resistant to movement of the wood  High tensile strength  Resistant to shear. 2 Description that includes two points, 2 marks. Allow 2 marks for single fully justified point. 10(a)(iii) Benefits of laminating will include:  Large stable section of wood is produced  Increased resistance to bending  Improved precision  Natural defects can be avoided  Consistent results in a batch. 2  1 marks 2 Allow other valid benefits. Do not allow cheap, easy. 10(b)(i) 6  1 marks 6 For Y allow compression. No mark for a row with more than two ticks. 10(b)(ii) Improvement identified in notes / sketches, 1 mark Force being resisted clearly identified, 1 mark Functional method, 1 mark. 3 Method Bending Compression Torsion Tension W X Y       Question Answer Marks Guidance 10(c)(i) Tie in suitable position, 1 mark. Suitable section of material shown, 1 mark. 2 10(c)(ii) Strut in suitable position, 1 mark. Suitable section of material shown, 1 mark. 2 10(c)(iii) Suitable shape of plate, 1 mark. Suitable position, 1 mark. 2 Accept either position Question Answer Marks Guidance 10(d)(i) The limit stop is used to support the barrier in the down position, 1 mark. To avoid any strain on the motor, 1 mark. 2 Accept any other valid response. 10(d)(ii) 3  X = 0.8  245, 1 mark X = 196 / 3, 1 mark X = 65.3 N, 1 mark. 3 Award 3 marks for answer with no working.

This question in 0445/41 May/June 2022

11 Fig. 11.1 shows a hand-operated whisk. turning handle 12t gears beaters 60t gear Fig. 11.1 (a) Materials used in the whisk include stainless steel and nylon. (i) Give one property of each material that makes it suitable for the whisk. stainless steel … … nylon … … [2] (ii) The whisk turning handle operates a 60t bevel gear connected to drive two 12t bevel gears, each attached to a beater. Name the mechanism used in the turning handle. … [1] (iii) State the velocity ratio of the gears. … [2] (iv) The whisk turning handle can be operated comfortably at 30 rpm. Calculate the speed of each beater when the turning handle is operated at 30 rpm. … … … [2] (v) Describe the movement of one beater relative to the other. … … [2] (b) (i) Name three types of bearing commonly used in mechanisms. 1 … 2 … 3 … [3] (ii) Describe the purpose of a bearing in a mechanism. … … … [2] (iii) Use sketches and notes to show how a bearing can control end-to-end movement (thrust) on a shaft. [3] (c) (i) Describe the difference between a first, second and third order lever. … … … … [3] (ii) Explain why levers are important in hand operated machinery. … … … [2] (d) Fig. 11.2 shows a hoist that uses a compound pulley system to lift heavy loads. Fig. 11.2 (i) State the mechanical advantage of the pulley system. … [1] (ii) Calculate the force, in Newtons, needed to raise a mass of 200 kg using the pulley system. 1 kg = 9.81 N … … … [2]

25 marks

Mark scheme: 11(a)(i) Stainless steel properties - hygienic, will not rust or corrode, long lasting. Nylon – self-lubricating bearing / gear material, can be easily moulded, durable. 2 x 1 marks. 2 Allow ‘durable’ for stainless steel. 11(a)(ii) The mechanism in the turning handle is a crank. 1 11(a)(iii) Velocity ratio = 60 / 12 [1] = 5:1[1] Numerical answer, 1 mark. Given as a ratio, 1 mark. 2 5:1 2 marks 1:5 no mark unless the working is correct. 11(a)(iv) Speed of beaters = 30  5, 1 mark = 150 rpm 1 mark. 2 Award 2 marks for correct answer with no working. Allow ecf from (ii) 11(a)(v) Each beater will turn at the same speed as the other one, 1 mark They will turn in opposite directions, 1 mark. 2 11(b)(i) Types of bearings include, plain, ball, roller, 1 mark for each. 3 Accept ceramic, needle or self-aligning bearings. Question Answer Marks Guidance 11(b)(ii) The purpose if a bearing is to:  Provide support to a moving part of a mechanism.  Reduce friction between moving parts  Reduce wear in the mechanism parts  Support both radial and axial loads.  Reduce contact area. 2 Allow other relevant points. Description that includes two points, 2 marks. Allow 2 marks for single fully justified point. 11(b)(iii) Shaft shown or described in suitable position, 1 mark. Recognised type of thrust bearing used, ball, roller, plain, 1 mark Functional method used, 1 mark. 3 11(c)(i) Description to use relative positions of fulcrum, load and effort.  First Order is E F L with fulcrum in the centre.  Second order is E L F with load in the centre  Third order is effort in the centre, F E L 1 mark for each correct statement. 3  1 marks 3 11(c)(ii) Reasons for importance of levers in hand operated machinery will include:  To make operation of the machine easier, requiring less effort.  To provide a mechanical advantage  To reduce fatigue in workers  To make operation of the machine safer.  To allow more precise control  Gives feedback to user. 2  1 marks 2 Explanation with two points, 2 marks. Allow 2 marks for single fully justified point. 11(d)(i) The mechanical advantage is 8. 1 11(d)(ii) Effort needed to raise a mass of 200 kg is: 200 / 8, = 25 kg, 1 mark 25 kg = 25  9.81 = 245.25 N, 1 mark. 2 Allow ecf from (d)(i). Award 2 marks for answer with no working. ball bearing plain bearing

This question in 0445/41 May/June 2022

2 (a) Give two reasons why a designer would need to reduce friction in a mechanism. 1 … … 2 … … [2] (b) State two methods that can be used to reduce friction in a mechanism. 1 … 2 … [2]

4 marks

Mark scheme: 2(a) Reasons for reducing friction will include:  Reducing wear on parts  Lower running costs  Reduce noise  Improve efficiency in the mechanism  Reduce heat 2  1 marks. 2 Allow other valid reasons 2(b) Methods will include:  Use of lubrication  Use of bearings/bearing material  Reduction of area of mating parts  Use of materials with low coefficient of friction e.g. nylon 2  1 marks for valid methods. 2

This question in 0445/42 May/June 2022

4 Fig. 4.1 shows a clock that uses a mechanism to convert motion. pendulum Fig. 4.1 (a) State the type of motion produced by the pendulum. … [1] (b) State the type of motion produced by the clock hands. … [1]

2 marks

Mark scheme: 4(a) Oscillating motion is produced by the pendulum. 1 4(b) Rotary motion is produced by the clock hands. 1

This question in 0445/42 May/June 2022

10 Fig. 10.1 shows three methods of transmitting motion from one shaft to another. driver driver vee belt spur gears driver chain drive Fig. 10.1 (a) (i) Give one different benefit of each method. spur gears … … vee belt … … chain drive … … [3] (ii) Circle the area of the chain in Fig. 10.1 that is in tension during rotation in the direction shown. [1] (iii) Fig. 10.2 shows a joining link which tightens under tension and is often used to join the ends of a chain together. Fig. 10.2 Explain why it is better to use this link as a joining method rather than a rivet. … … … … [2] (iv) Fig. 10.3 shows a toothed belt drive. toothed belt Fig. 10.3 State one advantage of a toothed belt compared to a vee belt. … … [1] (b) Many machine drives use spur gears in the drive train. Use sketches and notes to show a method of adjusting two spur gears to mesh correctly. [4] (c) Fig. 10.4 shows the drive components on a pillar drill. cut-off switch cover driven pulley Ø 85 motor pulley Ø 36 vee belt motor Fig. 10.4 (i) Give two reasons for using a cover over the belt and pulley system. 1 … 2 … [2] (ii) Calculate the speed of the motor if the driven pulley is rotating at 890 rpm. … … … … [3] (iii) The vee belt is tensioned by using a lever between the motor and pillar before locking it in place as shown in Fig. 10.5. locking screw pillar motor lever pillar motor lever Fig. 10.5 State the order of lever that is used. … [1] (iv) Use sketches and notes to show how the effort applied to the lever, when adjusting the belt, could be reduced. [2] (d) Fig. 10.6 shows two gear systems that result in the same reduction of 25:1. 8t 25t 40t 40t 8t and 40t gear fixed on one shaft Fig. 10.6 State two benefits of using the worm gear arrangement rather than the spur gears. 1 … … 2 … … [2] (e) Use the terms given below to complete the methods of converting motion. Each term may be used once, more than once, or not at all. rack and pinion cam and follower screw thread crank and slider compound pulley Conversion for rotary to linear movement can be carried out using a … or a … Conversion from rotary to reciprocating movement can be carried out using a … or a … [4]

25 marks

Mark scheme: 10(a)(i) Spur gears benefit – direct connection, no slipping, ratio can be adjusted, compound gear trains can be used, direction of rotation can be changed, does not take up much space, 1 mark. Vee belt benefit – not as likely to slip as a flat belt, allows pulleys to be spaced apart from each other, reduced noise, limited slip can take place, 1 mark. Chain drive benefit – no chance of slipping, axles can be some way apart, chain will last longer than a vee belt, high torque transfer 1 mark. method. 10(a)(ii) 1 Accept circle anywhere on top portion of chain. driver area of chain in tension Question Answer Marks Guidance 10(a)(iii) Benefits of the joining link are:  It is quicker to join chain  Joining link is removable to change / maintain the chain  Does not increase width of chain  No danger of over tightening and causing a link joint to be stiff. 2 1 mark for each valid benefit. 2  1 marks 10(a)(iv) Advantages of the toothed belt are:  A toothed belt cannot slip / more friction with toothed belt  Will allow the two pulleys to retain their relative position. 1 1 mark for valid answer. 10(b) Adjustment for one or both gears shown, 1 mark. Clear sketches or description, 1 mark. Method of fixing the gears into position e.g. nut / bolt shown, 1 mark. Functional solution for fixing, [1]. 4 10(c)(i) Reasons for cover will include:  Safety, nothing can get caught in moving belt  Prevent any dust particles of belt from being breathed in by operator  To operate the cut-off switch that controls power to motor  If belt breaks it will contain the broken parts of belt. 2  1 marks. 2 Allow any other valid reasons 10(c)(ii)  Driven pulley  890 =  driver pulley  driver rpm 85  890 = 36  driver rpm, [1]. 85  890 / 36 = driver rpm, [1]. = 2101.4 rpm, [1]. 3 Award 3 marks for correct answer with no working. 10(c)(iii) First order lever is used. 1 Question Answer Marks Guidance 10(c)(iv) Notes and sketches to indicate that lever length is extended, [1]. Justification given for reduction in effort, [1]. 2 Allow a method that reduces the distance between fulcrum and load. 10(d) Benefits of the worm gear include:  Takes up less space than spur gears  Reduced friction as less contact area on teeth  Large reduction ratio possible  Direction of motion is changed by 90°  Worm gear cannot slip backwards. 2  1 marks. 2 Allow any other valid benefits 10(e) Rotary to linear movement: Rack and pinion or screw thread, 2  1 marks. Rotary to reciprocating movement Cam and follower or crank and slider, 2  1 marks. 4

This question in 0445/42 May/June 2022

4 State two purposes of oil in a car engine. 1 … 2 … [2]

2 marks

Mark scheme: 4 Oil is used in a car engine to:  Lubricate the moving parts  Reduce friction  Prevent metal to metal contact  Remove grit / metal fragments from the moving parts  Assist with cooling of the engine. 2  1 marks.

This question in 0445/43 May/June 2022

5 Fig. 5.1 shows two examples of conversion of motion. … … follower to to … … pencil sharpener pencil cam Fig. 5.1 For each example complete the labels in Fig. 5.1 to show the conversion of motion. [4]

4 marks

Mark scheme: 5 1 mark for each correct label, 4  1 marks. 4

This question in 0445/43 May/June 2022

10 Fig. 10.1 shows views of a wooden aircraft propeller made from a number of layers of hardwood glued together. Fig. 10.1 (a) (i) Name the method of construction that has been used to produce the propeller. … [1] (ii) Describe the properties that are required in the adhesive that is used to glue the hardwood layers together. … … … [2] (iii) Give two benefits to the manufacturer of using this method of construction to produce the propeller. 1 … … 2 … … [2] (b) Fig. 10.2 shows three methods of extending the length of a piece of steel tube. W X Y Fig. 10.2 (i) Complete Table 10.1 by adding ticks (3), to show two forces that, when applied to the extended length of tube, will be best resisted by each method. Table 10.1 Method Bending Torsion Compression Tension W X Y [6] (ii) For one of the methods used in part (b)(i), use sketches and notes to show an improvement that will allow it to resist greater force. Identify the greater forces being resisted. [3] (c) Fig. 10.3 shows two views of a wall bracket to hold a hanging basket for flowers. A B Fig. 10.3 (i) On view A draw a tie on the bracket to prevent the arm from bending. [2] (ii) On view B draw a strut that will prevent the arm from bending. [2] (iii) Add a gusset plate to view B to increase resistance to bending. [2] (d) Fig. 10.4 shows a car park barrier that can be raised or lowered by an electric motor to allow cars through. 3 m 0.8 m limit stop X 245 N Fig. 10.4 (i) Explain why a limit stop is used on the barrier. … … … … [2] (ii) Calculate the force required at point X needed to keep the barrier in equilibrium. … … … … [3]

25 marks

Mark scheme: 10(a)(i) Lamination is the method of construction 1 10(a)(ii) Properties of adhesive could include:  Must be waterproof / water resistant  Gap filling  Resistant to movement of the wood  High tensile strength  Resistant to shear. 2 Description that includes two points, 2 marks. Allow 2 marks for single fully justified point. 10(a)(iii) Benefits of laminating will include:  Large stable section of wood is produced  Increased resistance to bending  Improved precision  Natural defects can be avoided  Consistent results in a batch. 2  1 marks 2 Allow other valid benefits. Do not allow cheap, easy. 10(b)(i) 6  1 marks 6 For Y allow compression. No mark for a row with more than two ticks. 10(b)(ii) Improvement identified in notes / sketches, 1 mark Force being resisted clearly identified, 1 mark Functional method, 1 mark. 3 Method Bending Compression Torsion Tension W X Y       Question Answer Marks Guidance 10(c)(i) Tie in suitable position, 1 mark. Suitable section of material shown, 1 mark. 2 10(c)(ii) Strut in suitable position, 1 mark. Suitable section of material shown, 1 mark. 2 10(c)(iii) Suitable shape of plate, 1 mark. Suitable position, 1 mark. 2 Accept either position Question Answer Marks Guidance 10(d)(i) The limit stop is used to support the barrier in the down position, 1 mark. To avoid any strain on the motor, 1 mark. 2 Accept any other valid response. 10(d)(ii) 3  X = 0.8  245, 1 mark X = 196 / 3, 1 mark X = 65.3 N, 1 mark. 3 Award 3 marks for answer with no working.

This question in 0445/43 May/June 2022

11 Fig. 11.1 shows a hand-operated whisk. turning handle 12t gears beaters 60t gear Fig. 11.1 (a) Materials used in the whisk include stainless steel and nylon. (i) Give one property of each material that makes it suitable for the whisk. stainless steel … … nylon … … [2] (ii) The whisk turning handle operates a 60t bevel gear connected to drive two 12t bevel gears, each attached to a beater. Name the mechanism used in the turning handle. … [1] (iii) State the velocity ratio of the gears. … [2] (iv) The whisk turning handle can be operated comfortably at 30 rpm. Calculate the speed of each beater when the turning handle is operated at 30 rpm. … … … [2] (v) Describe the movement of one beater relative to the other. … … [2] (b) (i) Name three types of bearing commonly used in mechanisms. 1 … 2 … 3 … [3] (ii) Describe the purpose of a bearing in a mechanism. … … … [2] (iii) Use sketches and notes to show how a bearing can control end-to-end movement (thrust) on a shaft. [3] (c) (i) Describe the difference between a first, second and third order lever. … … … … [3] (ii) Explain why levers are important in hand operated machinery. … … … [2] (d) Fig. 11.2 shows a hoist that uses a compound pulley system to lift heavy loads. Fig. 11.2 (i) State the mechanical advantage of the pulley system. … [1] (ii) Calculate the force, in Newtons, needed to raise a mass of 200 kg using the pulley system. 1 kg = 9.81 N … … … [2]

25 marks

Mark scheme: 11(a)(i) Stainless steel properties - hygienic, will not rust or corrode, long lasting. Nylon – self-lubricating bearing / gear material, can be easily moulded, durable. 2 x 1 marks. 2 Allow ‘durable’ for stainless steel. 11(a)(ii) The mechanism in the turning handle is a crank. 1 11(a)(iii) Velocity ratio = 60 / 12 [1] = 5:1[1] Numerical answer, 1 mark. Given as a ratio, 1 mark. 2 5:1 2 marks 1:5 no mark unless the working is correct. 11(a)(iv) Speed of beaters = 30  5, 1 mark = 150 rpm 1 mark. 2 Award 2 marks for correct answer with no working. Allow ecf from (ii) 11(a)(v) Each beater will turn at the same speed as the other one, 1 mark They will turn in opposite directions, 1 mark. 2 11(b)(i) Types of bearings include, plain, ball, roller, 1 mark for each. 3 Accept ceramic, needle or self-aligning bearings. Question Answer Marks Guidance 11(b)(ii) The purpose if a bearing is to:  Provide support to a moving part of a mechanism.  Reduce friction between moving parts  Reduce wear in the mechanism parts  Support both radial and axial loads.  Reduce contact area. 2 Allow other relevant points. Description that includes two points, 2 marks. Allow 2 marks for single fully justified point. 11(b)(iii) Shaft shown or described in suitable position, 1 mark. Recognised type of thrust bearing used, ball, roller, plain, 1 mark Functional method used, 1 mark. 3 11(c)(i) Description to use relative positions of fulcrum, load and effort.  First Order is E F L with fulcrum in the centre.  Second order is E L F with load in the centre  Third order is effort in the centre, F E L 1 mark for each correct statement. 3  1 marks 3 11(c)(ii) Reasons for importance of levers in hand operated machinery will include:  To make operation of the machine easier, requiring less effort.  To provide a mechanical advantage  To reduce fatigue in workers  To make operation of the machine safer.  To allow more precise control  Gives feedback to user. 2  1 marks 2 Explanation with two points, 2 marks. Allow 2 marks for single fully justified point. 11(d)(i) The mechanical advantage is 8. 1 11(d)(ii) Effort needed to raise a mass of 200 kg is: 200 / 8, = 25 kg, 1 mark 25 kg = 25  9.81 = 245.25 N, 1 mark. 2 Allow ecf from (d)(i). Award 2 marks for answer with no working. ball bearing plain bearing

This question in 0445/43 May/June 2022

4 Use sketches to show an example of: • a first order lever • a third order lever. first order lever third order lever [2]

2 marks

Mark scheme: 4 • First order lever, 1 mark 2 Drawing must be above the correct heading • Third order lever, 1 mark unless a separate heading has been used.

This question in 0445/42 Oct/Nov 2022

5 Give three reasons for choosing to use spur gears to transmit motion in a mechanism. 1 … … 2 … … 3 … … [3]

3 marks

Mark scheme: 5 Reasons for using spur gears include: 3 Allow other valid reasons. • To connect two shafts together / transmitting rotary motion • The gears will not slip • Gear ratio is easily changed • Transfer / increase torque effectively • Can be easily reversed by using an idler gear • Low cost materials can be used, e.g. nylon. 3  1 marks

This question in 0445/42 Oct/Nov 2022

6 Fig. 6.1 shows a method of providing lubrication to a mechanism. oil Fig. 6.1 (a) Give two benefits of providing lubrication by the method shown in Fig. 6.1. 1 … … 2 … … [2] (b) Explain why lubrication is important in a mechanism with moving parts. … … … … [2]

4 marks

Mark scheme: 6(a) Benefits include: 2 To gain marks the response must refer to • Visible reference to level of oil remaining the method of lubrication. • Gravity fed, does not rely on a pump • More efficient than hand lubrication • Low maintenance system • Regular feed of oil to the mechanism. • No spilled oil on surrounding parts 2  1 marks 6(b) Explanation should include the following points: 2 One mark for each point mentioned. • Reduced friction / efficiency is increased Allow two marks for a single point fully • Lubrication will prevent wear / corrosion in the mechanism components explained. • Mechanism is kept cool Allow reference to smooth running. • Reduced noise from the mechanism • Dirt or debris is carried away from the moving parts • Build-up of heat due to friction is reduced.

This question in 0445/42 Oct/Nov 2022

11 Fig. 11.1 shows a bolt with a screw thread cut into it. 54 1.75 9.85 12.00 0.87 Fig. 11.1 (a) (i) State the conversion of motion that takes place when using a screw thread. … to … [1] (ii) Screw threads are made in standard sizes. Give two benefits of using standard sizes of thread. 1 … 2 … [2] (iii) State which two dimensions in Fig. 11.1 form part of the standard size for the thread. 1 … 2 … [2] (b) Fig. 11.2 shows two types of clothes peg used to secure clothes to a washing line. Both types of clothes peg use leverage when in use. soft plastic wood hard plastic A B Fig. 11.2 (i) Mark the position of the fulcrum on peg A. [1] (ii) Describe the difference in operation of the springs in each clothes peg. … … … … [2] (iii) Explain why peg A is considered a more sustainable product than peg B. … … … … [2] (c) Fig. 11.3 shows a derailleur gear mechanism on a bicycle. 28 t sprocket jockey wheels Fig. 11.3 (i) Describe the purpose of the derailleur gear mechanism. … … … … [2] (ii) The jockey wheels use sealed ball bearings to allow free rotation. Give two reasons why this method has been chosen rather than individual ball bearings. 1 … … 2 … … [2] (iii) The chainwheel that drives the bicycle has 49 teeth. Calculate the Velocity Ratio when the chain is on the 28-tooth rear sprocket as shown in Fig. 11.4. 28 t rear sprocket 49 t chainwheel Fig. 11.4 … … … … [2] (iv) Calculate the speed of the rear wheel if the chainwheel is rotating at 78 rpm. … … … … [2] (v) Explain why the drive system will not be 100% efficient. … … … … … [3] (d) Fig. 11.5 shows a linkage used to operate railway signals. A B grease points fixed pivots Fig. 11.5 (i) Give two reasons why grease has been used to lubricate the moving parts of the linkage rather than oil. 1 … 2 … [2] (ii) Describe the effect on the linkage of moving rod A in the direction of the arrow. … … … … [2]

25 marks

Mark scheme: 11(a)(i) Rotary to Linear, 1 mark. 1 11(a)(ii) Benefits will include: 2 Allow other valid benefits. • Reduced stock • Interchangeability of components • Helps global manufacturing • Easier to get spare / replacement parts. 2  1 marks 11(a)(iii) The thread diameter 12.00 mm (M12), 1 mark 2 The thread pitch 1.75mm, 1 mark. 11(b)(i) 1 Correctly marked fulcrum position, 1 mark. 11(b)(ii) In peg A the spring is under torsion when the peg is opened, 1 mark 2 For peg A allow tension. In peg B the spring is compressed when the peg is opened, 1 mark. 11(b)(iii) Points will include: 2 Allow other valid points. • The wooden parts of the peg have come from a sustainable resource 1 mark for each valid point mentioned in • The two types of plastic bonded together in peg B prevents recycling explanation. • The plastic comes from a non-renewable resource. Allow 2 marks for single point fully explained. 11(c)(i) The purpose of the mechanism is: 2 Allow 1 mark for the benefits of using a • To move the chain from one sprocket to another lower gear. • To keep the chain in tension. 2  1 marks 11(c)(ii) • Individual bearings make maintenance more difficult 2 • A sealed bearing will not allow water or grit to enter • To prevent individual bearings falling out during maintenance • The jockey wheel will last longer. 2  1 marks 11(c)(iii) Velocity ratio = driver gear / driven gear, 1 mark 2 Allow 7:4 49 / 28 = 1.75, 1 mark 11(c)(iv) Rear wheel speed = chainwheel speed  VR, 1 mark 2 Award both marks for correct answer with 78  1.75 = 136.5 rpm, 1 mark no working. Allow ecf. 11(c)(v) The efficiency of the drive system will be reduced by: 3 One mark for each point mentioned. • Friction in all the moving parts Allow two marks for a single point fully • Sound created by the drive system, explained. • Heat generated by the moving parts • Lack of lubrication of moving part 11(d)(i) Reasons for using grease include: 2 Reasons given must compare the use of • Oil could drain away from the lubrication point grease to the use of oil. • Rain / snow could quickly wash oil away • Excessive heat in the summer would dry the oil up • Reduced chance of grit gaining access to the pivots. 2  1 marks. 11(d)(ii) If rod A is moved to the left: 2 One mark each for any two points • The LH bell crank will rotate anti-clockwise about the fixed pivot. mentioned. • The central link is then pushed to the right. • The RH bell crank rotates clockwise about the fixed pivot. • Rod B moves to the right, in the opposite direction to rod A

This question in 0445/42 Oct/Nov 2022

4 Use sketches to show an example of: • a first order lever • a third order lever. first order lever third order lever [2]

2 marks

Mark scheme: 4 • First order lever, 1 mark 2 Drawing must be above the correct heading • Third order lever, 1 mark unless a separate heading has been used.

This question in 0445/43 Oct/Nov 2022

5 Give three reasons for choosing to use spur gears to transmit motion in a mechanism. 1 … … 2 … … 3 … … [3]

3 marks

Mark scheme: 5 Reasons for using spur gears include: 3 Allow other valid reasons. • To connect two shafts together / transmitting rotary motion • The gears will not slip • Gear ratio is easily changed • Transfer / increase torque effectively • Can be easily reversed by using an idler gear • Low cost materials can be used, e.g. nylon. 3  1 marks

This question in 0445/43 Oct/Nov 2022

6 Fig. 6.1 shows a method of providing lubrication to a mechanism. oil Fig. 6.1 (a) Give two benefits of providing lubrication by the method shown in Fig. 6.1. 1 … … 2 … … [2] (b) Explain why lubrication is important in a mechanism with moving parts. … … … … [2]

4 marks

Mark scheme: 6(a) Benefits include: 2 To gain marks the response must refer to • Visible reference to level of oil remaining the method of lubrication. • Gravity fed, does not rely on a pump • More efficient than hand lubrication • Low maintenance system • Regular feed of oil to the mechanism. • No spilled oil on surrounding parts 2  1 marks 6(b) Explanation should include the following points: 2 One mark for each point mentioned. • Reduced friction / efficiency is increased Allow two marks for a single point fully • Lubrication will prevent wear / corrosion in the mechanism components explained. • Mechanism is kept cool Allow reference to smooth running. • Reduced noise from the mechanism • Dirt or debris is carried away from the moving parts • Build-up of heat due to friction is reduced.

This question in 0445/43 Oct/Nov 2022

11 Fig. 11.1 shows a bolt with a screw thread cut into it. 54 1.75 9.85 12.00 0.87 Fig. 11.1 (a) (i) State the conversion of motion that takes place when using a screw thread. … to … [1] (ii) Screw threads are made in standard sizes. Give two benefits of using standard sizes of thread. 1 … 2 … [2] (iii) State which two dimensions in Fig. 11.1 form part of the standard size for the thread. 1 … 2 … [2] (b) Fig. 11.2 shows two types of clothes peg used to secure clothes to a washing line. Both types of clothes peg use leverage when in use. soft plastic wood hard plastic A B Fig. 11.2 (i) Mark the position of the fulcrum on peg A. [1] (ii) Describe the difference in operation of the springs in each clothes peg. … … … … [2] (iii) Explain why peg A is considered a more sustainable product than peg B. … … … … [2] (c) Fig. 11.3 shows a derailleur gear mechanism on a bicycle. 28 t sprocket jockey wheels Fig. 11.3 (i) Describe the purpose of the derailleur gear mechanism. … … … … [2] (ii) The jockey wheels use sealed ball bearings to allow free rotation. Give two reasons why this method has been chosen rather than individual ball bearings. 1 … … 2 … … [2] (iii) The chainwheel that drives the bicycle has 49 teeth. Calculate the Velocity Ratio when the chain is on the 28-tooth rear sprocket as shown in Fig. 11.4. 28 t rear sprocket 49 t chainwheel Fig. 11.4 … … … … [2] (iv) Calculate the speed of the rear wheel if the chainwheel is rotating at 78 rpm. … … … … [2] (v) Explain why the drive system will not be 100% efficient. … … … … … [3] (d) Fig. 11.5 shows a linkage used to operate railway signals. A B grease points fixed pivots Fig. 11.5 (i) Give two reasons why grease has been used to lubricate the moving parts of the linkage rather than oil. 1 … 2 … [2] (ii) Describe the effect on the linkage of moving rod A in the direction of the arrow. … … … … [2]

25 marks

Mark scheme: 11(a)(i) Rotary to Linear, 1 mark. 1 11(a)(ii) Benefits will include: 2 Allow other valid benefits. • Reduced stock • Interchangeability of components • Helps global manufacturing • Easier to get spare / replacement parts. 2  1 marks 11(a)(iii) The thread diameter 12.00 mm (M12), 1 mark 2 The thread pitch 1.75mm, 1 mark. 11(b)(i) 1 Correctly marked fulcrum position, 1 mark. 11(b)(ii) In peg A the spring is under torsion when the peg is opened, 1 mark 2 For peg A allow tension. In peg B the spring is compressed when the peg is opened, 1 mark. 11(b)(iii) Points will include: 2 Allow other valid points. • The wooden parts of the peg have come from a sustainable resource 1 mark for each valid point mentioned in • The two types of plastic bonded together in peg B prevents recycling explanation. • The plastic comes from a non-renewable resource. Allow 2 marks for single point fully explained. 11(c)(i) The purpose of the mechanism is: 2 Allow 1 mark for the benefits of using a • To move the chain from one sprocket to another lower gear. • To keep the chain in tension. 2  1 marks 11(c)(ii) • Individual bearings make maintenance more difficult 2 • A sealed bearing will not allow water or grit to enter • To prevent individual bearings falling out during maintenance • The jockey wheel will last longer. 2  1 marks 11(c)(iii) Velocity ratio = driver gear / driven gear, 1 mark 2 Allow 7:4 49 / 28 = 1.75, 1 mark 11(c)(iv) Rear wheel speed = chainwheel speed  VR, 1 mark 2 Award both marks for correct answer with 78  1.75 = 136.5 rpm, 1 mark no working. Allow ecf. 11(c)(v) The efficiency of the drive system will be reduced by: 3 One mark for each point mentioned. • Friction in all the moving parts Allow two marks for a single point fully • Sound created by the drive system, explained. • Heat generated by the moving parts • Lack of lubrication of moving part 11(d)(i) Reasons for using grease include: 2 Reasons given must compare the use of • Oil could drain away from the lubrication point grease to the use of oil. • Rain / snow could quickly wash oil away • Excessive heat in the summer would dry the oil up • Reduced chance of grit gaining access to the pivots. 2  1 marks. 11(d)(ii) If rod A is moved to the left: 2 One mark each for any two points • The LH bell crank will rotate anti-clockwise about the fixed pivot. mentioned. • The central link is then pushed to the right. • The RH bell crank rotates clockwise about the fixed pivot. • Rod B moves to the right, in the opposite direction to rod A

This question in 0445/43 Oct/Nov 2022

2 Fig. 2.1 shows a diving springboard. X springboard Fig. 2.1 (a) Name one force that will act on the springboard, causing it to deform, when a diver jumps up and lands at point X. … [1] (b) The motion of the diver jumping and landing at point X will be converted into movement of the springboard. State the conversion of motion that will be caused by the diver jumping up and landing at point X. … motion to … motion. [2]

3 marks

Mark scheme: 2(a) Bending force [1] 1 2(b) Reciprocating motion [1] to oscillating motion [1]. 2

This question in 0445/41 May/June 2023

4 Fig. 4.1 shows two arrangements of spur gears. driver driver driven driven A B Fig. 4.1 Describe the changes in output that will occur for each arrangement of spur gears. A … … … B … … … [4]

4 marks

Mark scheme: 4 A – driven gear will rotate slower [1] and in the opposite direction [1] B – driven gear will rotate at the same speed [1] as driver and in the same direction [1] 4 Allow marks for understanding shown

This question in 0445/41 May/June 2023

5 Give one reason for lubricating steel spur gears in a mechanism. … … [1]

1 marks

Mark scheme: 5 Any 1 suitable reason: Lubrication will reduce wear in the gears [1] Reduce friction and heat build-up [1] Smoother running [1] 1

This question in 0445/41 May/June 2023

6 Give one result of not lubricating a mechanism running at high speed. … … [1]

1 marks

Mark scheme: 6 Any 1 suitable result: Teeth on gear will be damaged or could melt [1] Excessive noise from the gears [1] Mechanism sticks / breaks down [1] 1 Allow reference to increased wear on parts

This question in 0445/41 May/June 2023

11 Fig. 11.1 shows a water spray bottle operated by finger pressure on the operating lever. operating lever Fig. 11.1 (a) (i) Add the letters ‘L’, ‘F’ and ‘E’ to the correct circles in Fig. 11.1 to identify the positions of the load (L), fulcrum (F) and effort (E) on the operating lever. [3] (ii) Explain what is meant by the mechanical advantage of a lever. … … … [2] (iii) Give one way of increasing the mechanical advantage of the lever in Fig. 11.1. … … [1] (iv) State the order of lever used in the water spray bottle. … [1] (b) Fig. 11.2 shows a locomotive used on a rack and pinion mountain railway. The powered driving wheel on each side is connected to the other wheels with link rods. link rod steel rail rack pinion cut-out steel driving wheel Fig. 11.2 (i) Explain why the rack and pinion gear is used in addition to a conventional system that relies on friction between the driving wheels and the rails. … … … … [3] (ii) Give two different uses for a rack and pinion gear. 1 … 2 … [2] (iii) Describe the reason for using link rods to connect the wheels rather than gears or a belt and pulley. … … … [2] (iv) The driving wheels have cut-outs to reduce weight. The area opposite to where the link rods are fitted is left solid. Give two ways that these features can improve the efficiency of the drive system. 1 … … 2 … … [2] (c) Fig. 11.3 shows a clock with an enlarged view of the winding mechanism and the key used to wind the clock. square shaft for key key winding mechanism Fig. 11.3 (i) Draw on the enlarged view in Fig. 11.3 to show the direction that the key will be turned. [1] (ii) Name the winding mechanism in Fig. 11.3. … and … [2] (iii) Describe the reason for using this mechanism. … … … … [2] (d) Fig. 11.4 shows a compound gear train. The 15 t and 30 t gears B are locked together by a pin. C locking pin B D A 15 t 30 t 30 t 15 t 60 t Fig. 11.4 Calculate the speed of the driven gear D when the driver gear A rotates at 336 rpm. … … … … … [4]

25 marks

Mark scheme: 11(a)(i) 3 1 mark for each correct Max. 2 if one of spare circles used Max. 1 if both spare circles used 11(a)(ii) Amplification of effort into a greater force applied to the load – increase in force measured as a number [1] A trade-off of input force against movement (larger movement and smaller force transferred into smaller movement but greater force [1] Load / effort [1] 2 2  1 marks for basic points given Award 2 marks for a single point fully explained 11(a)(iii) MA can be increased by either: Extending the length of the lever [1] OR Moving the load closer to the fulcrum [1] 1 11(a)(iv) The lever is second class. 1 11(b)(i) Explanation could include:  On steep gradient the friction between train and rails will reduc  Conventional system can be used when possible to reduce fuel use  The rack and pinion is a positive form of drive that will ensure no slipping of wheels on rails 3 Allow other valid points Explanation with three points made [3] Award 2 marks for a single fully justified point 11(b)(ii) Any valid use of rack and pinion [2 x 1] E.g. vehicle steering, pillar drill, bandsaw, microscope, tripod 2 11(b)(iii) Any 2 valid points such as:  The link rods do not require wheels to be close together  There will be no chance of belt slipping  The train is a very heavy load that would put undue stress onto a gear system  Reduced component count 2 Allow other valid points 2  1 marks for basic points given Award 2 marks for a single point fully explained Question Answer Marks Guidance 11(b)(iv) Any 2 valid points such as: With no cut-outs the wheels would not be in balance, weight of link rods would cause imbalance [1] Drive on rails would not be smooth [1] Vibration would be caused leading to loss of efficiency [1] 2 Allow other valid points 11(c)(i) The key will turn in an anti-clockwise direction 1 11(c)(ii) Ratchet [1] and pawl [1] 2 Allow ‘click’ for pawl 11(c)(iii) The mechanism allows the spring to be tensioned by winding it [1] It does not allow the spring to immediately unwind [1] 2 11(d) Gear ratio A:B = 2:1 [1] Gear ratio B:D = 2:1 [1] Gear C is an idler which does not affect the ratio Total reduction = 2  2 = 4:1 [1] If A rotates at 336 rpm gear D speed = 336 / 4 = 84 rpm [1] 4 If correct answer is given with no working award 4 marks

This question in 0445/41 May/June 2023

5 Fig. 5.1 shows a mechanism made up of different linkages. link D link C crank Fig. 5.1 (a) State the type of motion of link C when the crank is turned. … [1] (b) State the type of motion of link D when the crank is turned. … [1] (c) Give two reasons for providing lubrication to the linkages. 1 … … 2 … … [2]

4 marks

Mark scheme: 5(a) Reciprocating [1] 1 5(b) Oscillating [1] 1 5(c) Any 2 reasons for lubrication such as: Reduce friction [1] Reduction of wear in parts [1] Smoother running [1] Quieter operation [1] Reduction in overheating [1] 2 Allow other valid alternatives.

This question in 0445/42 May/June 2023

6 Fig. 6.1 shows two spur gears. 24 t 24 t drive gear Fig. 6.1 State two results of rotating the drive gear in the direction shown. 1 … … 2 … … [2]

2 marks

Mark scheme: 6 The gears will rotate at the same speed (VR is the same) [1] The gears will rotate in opposite directions (driven gear anticlockwise) [1] 2 Allow ‘rotation at the same torque’

This question in 0445/42 May/June 2023

11 (a) Fig. 11.1 shows a part of a bicycle chain with four positions identified. B C A D Fig. 11.1 (i) Give the two positions on Fig. 11.1 where lubrication should be applied. 1 … 2 … [2] (ii) Name the type of lubrication that would be suitable for the chain. … [1] (iii) State the force that will be applied to the chain when it is used to drive a single sprocket. … [1] (iv) Describe one advantage that a chain drive has when compared to spur gears. … … … [2] (b) Fig. 11.2 shows a cam with the direction of rotation indicated. follower position X Y Z W Fig. 11.2 (i) Complete Table 11.1 to show the positions of dwell, fall and rise on the cam. Table 11.1 position on cam type of movement W Z Y X [4] (ii) Use sketches and notes to show two types of follower that would be suitable for use with the cam. [2] (iii) State the type of cam that can only be rotated in one direction. … [1] (iv) Explain why rotating the cam shown in Fig. 11.2 at high speed could result in loss of efficiency. … … … … [2] (c) (i) Use sketches and notes to show the difference between axial load and radial load when using bearings. [2] (ii) Three different types of ball bearing are shown in Fig. 11.3. B loose in a cage A fixed in a cage C sealed for life Fig. 11.3 Give one benefit for each type of ball bearing. A … B … C … [3] (d) (i) Fig. 11.4 shows a woodworker’s G cramp. thread pitch 2.0 mm mm 60 Fig. 11.4 Calculate the velocity ratio of the thread in the G cramp. distance moved by effort Use the formula: VR = distance moved by load … … … … [3] (ii) State the conversion of motion that takes place when using screw threads. … to … [2]

25 marks

Mark scheme: 11(a)(i) Lubrication should be applied at B and C [2 x 1] 2 11(a)(ii) Oil should be applied 1 Accept any suitable named type /brand 11(a)(iii) Tension is applied to the chain 1 11(a)(iv) Any 2 advantages of a chain drive such as:  Sprockets can be placed any distance apart no precision needed  Less likelihood of damage to sprockets if drive system is blocked  Different gear ratios can be applied easily  Low maintenance system 2 Description to include any two valid points [2] Full description of a single point [2] Recognition that the driver and driven gears will turn in the same direction 11(b)((i) [4 x 1] 4 11(b)(ii) Award marks for any recognised type of follower, e.g. roller / knife edge 2 11(b)(iii) The snail cam can only be rotated in one direction [1] 1 Allow drop cam 11(b)(iv) Explanation may include:  Bounce in follower at high speed  Excessive wear in follower  Excessive noise 2 Allow any other valid points Explanation to include any two valid points [2] Full description of a single point [2] Question Answer Marks Guidance 11(c)(i) [2 x 1] 2 Do not allow cost related benefits 11(c)(ii) Example benefits for: A – bearings cannot fall out / easy to re-pack with grease [1] B – bearings can be removed for cleaning during maintenance / easy to examine individual components for wear/damage / more compact [1] C – dirt/debris cannot enter bearing area / maintenance free [1] 3 Allow other valid responses 11(d)(i) Distance moved by effort = Π  2  60 or Π  120 = 376.99 [1] Distance moved by load = 2.0 mm [1] 376.99 / 2 = 188.496 [1] 3 Allow rounding differences in final answer Correct answer with no working [3] 11(d)(ii) Rotary [1] motion is converted to linear [1] motion. 2

This question in 0445/42 May/June 2023

2 Fig. 2.1 shows a diving springboard. X springboard Fig. 2.1 (a) Name one force that will act on the springboard, causing it to deform, when a diver jumps up and lands at point X. … [1] (b) The motion of the diver jumping and landing at point X will be converted into movement of the springboard. State the conversion of motion that will be caused by the diver jumping up and landing at point X. … motion to … motion. [2]

3 marks

Mark scheme: 2(a) Bending force [1] 1 2(b) Reciprocating motion [1] to oscillating motion [1]. 2

This question in 0445/43 May/June 2023

4 Fig. 4.1 shows two arrangements of spur gears. driver driver driven driven A B Fig. 4.1 Describe the changes in output that will occur for each arrangement of spur gears. A … … … B … … … [4]

4 marks

Mark scheme: 4 A – driven gear will rotate slower [1] and in the opposite direction [1] B – driven gear will rotate at the same speed [1] as driver and in the same direction [1] 4 Allow marks for understanding shown

This question in 0445/43 May/June 2023

5 Give one reason for lubricating steel spur gears in a mechanism. … … [1]

1 marks

Mark scheme: 5 Any 1 suitable reason: Lubrication will reduce wear in the gears [1] Reduce friction and heat build-up [1] Smoother running [1] 1

This question in 0445/43 May/June 2023

6 Give one result of not lubricating a mechanism running at high speed. … … [1]

1 marks

Mark scheme: 6 Any 1 suitable result: Teeth on gear will be damaged or could melt [1] Excessive noise from the gears [1] Mechanism sticks / breaks down [1] 1 Allow reference to increased wear on parts

This question in 0445/43 May/June 2023

11 Fig. 11.1 shows a water spray bottle operated by finger pressure on the operating lever. operating lever Fig. 11.1 (a) (i) Add the letters ‘L’, ‘F’ and ‘E’ to the correct circles in Fig. 11.1 to identify the positions of the load (L), fulcrum (F) and effort (E) on the operating lever. [3] (ii) Explain what is meant by the mechanical advantage of a lever. … … … [2] (iii) Give one way of increasing the mechanical advantage of the lever in Fig. 11.1. … … [1] (iv) State the order of lever used in the water spray bottle. … [1] (b) Fig. 11.2 shows a locomotive used on a rack and pinion mountain railway. The powered driving wheel on each side is connected to the other wheels with link rods. link rod steel rail rack pinion cut-out steel driving wheel Fig. 11.2 (i) Explain why the rack and pinion gear is used in addition to a conventional system that relies on friction between the driving wheels and the rails. … … … … [3] (ii) Give two different uses for a rack and pinion gear. 1 … 2 … [2] (iii) Describe the reason for using link rods to connect the wheels rather than gears or a belt and pulley. … … … [2] (iv) The driving wheels have cut-outs to reduce weight. The area opposite to where the link rods are fitted is left solid. Give two ways that these features can improve the efficiency of the drive system. 1 … … 2 … … [2] (c) Fig. 11.3 shows a clock with an enlarged view of the winding mechanism and the key used to wind the clock. square shaft for key key winding mechanism Fig. 11.3 (i) Draw on the enlarged view in Fig. 11.3 to show the direction that the key will be turned. [1] (ii) Name the winding mechanism in Fig. 11.3. … and … [2] (iii) Describe the reason for using this mechanism. … … … … [2] (d) Fig. 11.4 shows a compound gear train. The 15 t and 30 t gears B are locked together by a pin. C locking pin B D A 15 t 30 t 30 t 15 t 60 t Fig. 11.4 Calculate the speed of the driven gear D when the driver gear A rotates at 336 rpm. … … … … … [4]

25 marks

Mark scheme: 11(a)(i) 3 1 mark for each correct Max. 2 if one of spare circles used Max. 1 if both spare circles used 11(a)(ii) Amplification of effort into a greater force applied to the load – increase in force measured as a number [1] A trade-off of input force against movement (larger movement and smaller force transferred into smaller movement but greater force [1] Load / effort [1] 2 2  1 marks for basic points given Award 2 marks for a single point fully explained 11(a)(iii) MA can be increased by either: Extending the length of the lever [1] OR Moving the load closer to the fulcrum [1] 1 11(a)(iv) The lever is second class. 1 11(b)(i) Explanation could include:  On steep gradient the friction between train and rails will reduc  Conventional system can be used when possible to reduce fuel use  The rack and pinion is a positive form of drive that will ensure no slipping of wheels on rails 3 Allow other valid points Explanation with three points made [3] Award 2 marks for a single fully justified point 11(b)(ii) Any valid use of rack and pinion [2 x 1] E.g. vehicle steering, pillar drill, bandsaw, microscope, tripod 2 11(b)(iii) Any 2 valid points such as:  The link rods do not require wheels to be close together  There will be no chance of belt slipping  The train is a very heavy load that would put undue stress onto a gear system  Reduced component count 2 Allow other valid points 2  1 marks for basic points given Award 2 marks for a single point fully explained Question Answer Marks Guidance 11(b)(iv) Any 2 valid points such as: With no cut-outs the wheels would not be in balance, weight of link rods would cause imbalance [1] Drive on rails would not be smooth [1] Vibration would be caused leading to loss of efficiency [1] 2 Allow other valid points 11(c)(i) The key will turn in an anti-clockwise direction 1 11(c)(ii) Ratchet [1] and pawl [1] 2 Allow ‘click’ for pawl 11(c)(iii) The mechanism allows the spring to be tensioned by winding it [1] It does not allow the spring to immediately unwind [1] 2 11(d) Gear ratio A:B = 2:1 [1] Gear ratio B:D = 2:1 [1] Gear C is an idler which does not affect the ratio Total reduction = 2  2 = 4:1 [1] If A rotates at 336 rpm gear D speed = 336 / 4 = 84 rpm [1] 4 If correct answer is given with no working award 4 marks

This question in 0445/43 May/June 2023

4 Sketch and name one example of a third order lever. [2]

2 marks

Mark scheme: 4 Sketch of third order lever – shovels, fishing rods, human arms and legs, 2 springboard in a pool, tweezers, and ice tongs. [1] Correct name given to example. [1]

This question in 0445/41 Oct/Nov 2023

5 Fig. 5.1 shows a linkage used on a front loader truck. Fig. 5.1 (a) Name the type of linkage shown in Fig. 5.1. … [1] (b) Explain why this type of linkage has been chosen to connect the bucket to the truck. … … … [2] (c) Use sketches and notes to show a different type of linkage. [2]

5 marks

Mark scheme: 5(a) Parallel linkage [1]. 1 5(b) Explanation should include: 2 Explanation with two points made, [2]. Allow 2 marks for a single fully justified • As the bucket / container moves up it will stay parallel to the ground point. • Any liquid contents will not spill out. • Solids being lifted will not tip. • Increased visibility for truck operator. 5(c) Types of linkage shown could include: 2 Allow any recognised form of linkage apart from parallel motion. • Crank and slider • Crank and piston • Bell crank linkage • ‘Z’ bar linkage Clear sketch [1] notes to indicate how it works [1]

This question in 0445/41 Oct/Nov 2023

6 Fig. 6.1 shows a simplified line drawing of a small internal combustion (IC) engine. cylinder piston crankshaft Fig. 6.1 State the conversion of motion that takes place in the IC engine when the crankshaft is driven by the piston. … to … [2]

2 marks

Mark scheme: 6 Reciprocating motion [1] is converted to rotary motion [1] 2

This question in 0445/41 Oct/Nov 2023

10 (a) Fig. 10.1 shows a cam and follower mechanism. spring nylon bearing cam follower cam position Fig. 10.1 (i) Draw a cam on the position shown in Fig. 10.1 to operate the cam follower 4 times for each revolution of the cam. [2] (ii) State the purpose of the spring. … [1] (iii) The bearing supporting the follower is made from nylon. Give two properties of nylon that make it a suitable material for the bearing. 1 … … 2 … … [2] (b) Fig. 10.2 shows a toy gyroscope used to demonstrate how a spinning rotor can be used to stabilise motion. The rotor is made to spin by pulling on a string that is wrapped around the axle. hole for string plain bearing rotor string is used to spin the rotor axle plain bearing Fig. 10.2 (i) State the conversion of motion that takes place when the string is pulled. … to … [2] (ii) The axle is supported at each end by plain bearings. Explain what is meant by a plain bearing. … … … … [2] (iii) State two factors that will affect the length of time that the rotor will spin. 1 … … 2 … … [2] (c) Fig. 10.3 shows details of a vee belt and a flat belt that can drive a pulley in either direction. vee belt flat belt Fig. 10.3 (i) Give two advantages that the vee belt has when being used to drive a pulley on a machine. 1 … … 2 … … [2] (ii) Sketch the arrangement of the flat belt that will change the direction of the driven pulley. [1] (iii) Explain why the vee belt cannot change the direction of the driven pulley. … … … … [2] (iv) Use sketches and notes to show a method of tensioning a vee belt without changing the position of the pulleys. [3] (d) Fig. 10.4 shows a section through a car jack. 250 thread pitch 1.75 mm Fig. 10.4 (i) Calculate the velocity ratio (VR) of the car jack. … … … … [2] (ii) The car jack is 30% efficient. Give one reason for the loss of efficiency in the car jack. … … [1] (iii) Calculate the effort needed to lift a load of 5 kN, ignoring the loss of efficiency. … … … … [3]

25 marks

Mark scheme: 10(a)(i) 2 Square cam drawn [1] suitable proportions [1] 10(a)(ii) The spring ensures that the follower is always touching the cam. 1 Allow mark for understanding shown. 10(a)(iii) Mechanical property of nylon: 2 Do not accept cost related properties • Efficient bearing material • Self-lubricating • Does not corrode / durable • Ease of batch production – can be moulded Electrical property: • It is an insulator. [2  1] 10(b)(i) Linear motion is converted to rotary motion 2 10(b)(ii) Plain bearings: 2 1 mark for each point mentioned in explanation, up to 2 marks. • Are a plain surface • Reduces friction • With no rolling elements • They allow rotation between two parts 10(b)(iii) Factors will include: 2 Allow other valid points. • Adjustment of the plain bearing • Any additional lubrication added to bearing surfaces • Speed with which the string is pulled • Length of string wrapped around the spindle • Diameter / mass of rotor. [2  1] 10(c)(i) Advantages of the vee belt include: 2 Allow other valid advantages • Larger section so less likely to stretch • Vee belt will provide more grip when it is pulled into the vee of the pulley • Less likely to slip than a flat belt • Precise torque transfer between pulleys • Durable • Quieter when operating. [2  1] 10(c)(ii) Flat belt will be crossed over to reverse direction 1 10(c)(iii) Explanation to include: 2 Award marks for understanding shown in explanation. The thickness of the vee belt does not allow it to bend backwards [1] The outer surface of the vee would be next to the pulley [1] 10(c)(iv) Sketches and notes to indicate: 3 • Idler wheel pressed against the vee belt [1] • Method of adjusting the idler wheel [1] • Position of two pulleys is not altered [1] 10(d)(i) Distance moved by thread in 1 revolution = 1.75 mm 2 Allow rounding errors in calculation. Distance moved by handle =   2  250 = 1571 [1] VR = 1571 / 1.75 = 897.6, [1] 10(d)(ii) Loss of efficiency will be due to: 1 Allow mark for understanding shown. • Friction in the jack components • Heat • Sound 10(d)(iii) Effort = load / VR [1] 3 Allow ecf from (d)(i) = 5000 / 897.6 [1] = 5.57 N [1] Alternative method – (load  pitch) / effort distance [1] = (5000  .00175) ( x 2  250) [1] = 5.57 N [1]

This question in 0445/41 Oct/Nov 2023

4 Sketch and name one example of a third order lever. [2]

2 marks

Mark scheme: 4 Sketch of third order lever – shovels, fishing rods, human arms and legs, 2 springboard in a pool, tweezers, and ice tongs. [1] Correct name given to example. [1]

This question in 0445/42 Oct/Nov 2023

5 Fig. 5.1 shows a linkage used on a front loader truck. Fig. 5.1 (a) Name the type of linkage shown in Fig. 5.1. … [1] (b) Explain why this type of linkage has been chosen to connect the bucket to the truck. … … … [2] (c) Use sketches and notes to show a different type of linkage. [2]

5 marks

Mark scheme: 5(a) Parallel linkage [1]. 1 5(b) Explanation should include: 2 Explanation with two points made, [2]. Allow 2 marks for a single fully justified • As the bucket / container moves up it will stay parallel to the ground point. • Any liquid contents will not spill out. • Solids being lifted will not tip. • Increased visibility for truck operator. 5(c) Types of linkage shown could include: 2 Allow any recognised form of linkage apart from parallel motion. • Crank and slider • Crank and piston • Bell crank linkage • ‘Z’ bar linkage Clear sketch [1] notes to indicate how it works [1]

This question in 0445/42 Oct/Nov 2023

6 Fig. 6.1 shows a simplified line drawing of a small internal combustion (IC) engine. cylinder piston crankshaft Fig. 6.1 State the conversion of motion that takes place in the IC engine when the crankshaft is driven by the piston. … to … [2]

2 marks

Mark scheme: 6 Reciprocating motion [1] is converted to rotary motion [1] 2

This question in 0445/42 Oct/Nov 2023

10 (a) Fig. 10.1 shows a cam and follower mechanism. spring nylon bearing cam follower cam position Fig. 10.1 (i) Draw a cam on the position shown in Fig. 10.1 to operate the cam follower 4 times for each revolution of the cam. [2] (ii) State the purpose of the spring. … [1] (iii) The bearing supporting the follower is made from nylon. Give two properties of nylon that make it a suitable material for the bearing. 1 … … 2 … … [2] (b) Fig. 10.2 shows a toy gyroscope used to demonstrate how a spinning rotor can be used to stabilise motion. The rotor is made to spin by pulling on a string that is wrapped around the axle. hole for string plain bearing rotor string is used to spin the rotor axle plain bearing Fig. 10.2 (i) State the conversion of motion that takes place when the string is pulled. … to … [2] (ii) The axle is supported at each end by plain bearings. Explain what is meant by a plain bearing. … … … … [2] (iii) State two factors that will affect the length of time that the rotor will spin. 1 … … 2 … … [2] (c) Fig. 10.3 shows details of a vee belt and a flat belt that can drive a pulley in either direction. vee belt flat belt Fig. 10.3 (i) Give two advantages that the vee belt has when being used to drive a pulley on a machine. 1 … … 2 … … [2] (ii) Sketch the arrangement of the flat belt that will change the direction of the driven pulley. [1] (iii) Explain why the vee belt cannot change the direction of the driven pulley. … … … … [2] (iv) Use sketches and notes to show a method of tensioning a vee belt without changing the position of the pulleys. [3] (d) Fig. 10.4 shows a section through a car jack. 250 thread pitch 1.75 mm Fig. 10.4 (i) Calculate the velocity ratio (VR) of the car jack. … … … … [2] (ii) The car jack is 30% efficient. Give one reason for the loss of efficiency in the car jack. … … [1] (iii) Calculate the effort needed to lift a load of 5 kN, ignoring the loss of efficiency. … … … … [3]

25 marks

Mark scheme: 10(a)(i) 2 Square cam drawn [1] suitable proportions [1] 10(a)(ii) The spring ensures that the follower is always touching the cam. 1 Allow mark for understanding shown. 10(a)(iii) Mechanical property of nylon: 2 Do not accept cost related properties • Efficient bearing material • Self-lubricating • Does not corrode / durable • Ease of batch production – can be moulded Electrical property: • It is an insulator. [2  1] 10(b)(i) Linear motion is converted to rotary motion 2 10(b)(ii) Plain bearings: 2 1 mark for each point mentioned in explanation, up to 2 marks. • Are a plain surface • Reduces friction • With no rolling elements • They allow rotation between two parts 10(b)(iii) Factors will include: 2 Allow other valid points. • Adjustment of the plain bearing • Any additional lubrication added to bearing surfaces • Speed with which the string is pulled • Length of string wrapped around the spindle • Diameter / mass of rotor. [2  1] 10(c)(i) Advantages of the vee belt include: 2 Allow other valid advantages • Larger section so less likely to stretch • Vee belt will provide more grip when it is pulled into the vee of the pulley • Less likely to slip than a flat belt • Precise torque transfer between pulleys • Durable • Quieter when operating. [2  1] 10(c)(ii) Flat belt will be crossed over to reverse direction 1 10(c)(iii) Explanation to include: 2 Award marks for understanding shown in explanation. The thickness of the vee belt does not allow it to bend backwards [1] The outer surface of the vee would be next to the pulley [1] 10(c)(iv) Sketches and notes to indicate: 3 • Idler wheel pressed against the vee belt [1] • Method of adjusting the idler wheel [1] • Position of two pulleys is not altered [1] 10(d)(i) Distance moved by thread in 1 revolution = 1.75 mm 2 Allow rounding errors in calculation. Distance moved by handle =   2  250 = 1571 [1] VR = 1571 / 1.75 = 897.6, [1] 10(d)(ii) Loss of efficiency will be due to: 1 Allow mark for understanding shown. • Friction in the jack components • Heat • Sound 10(d)(iii) Effort = load / VR [1] 3 Allow ecf from (d)(i) = 5000 / 897.6 [1] = 5.57 N [1] Alternative method – (load  pitch) / effort distance [1] = (5000  .00175) ( x 2  250) [1] = 5.57 N [1]

This question in 0445/42 Oct/Nov 2023

4 Sketch and name one example of a third order lever. [2]

2 marks

Mark scheme: 4 Sketch of third order lever – shovels, fishing rods, human arms and legs, 2 springboard in a pool, tweezers, and ice tongs. [1] Correct name given to example. [1]

This question in 0445/43 Oct/Nov 2023

5 Fig. 5.1 shows a linkage used on a front loader truck. Fig. 5.1 (a) Name the type of linkage shown in Fig. 5.1. … [1] (b) Explain why this type of linkage has been chosen to connect the bucket to the truck. … … … [2] (c) Use sketches and notes to show a different type of linkage. [2]

5 marks

Mark scheme: 5(a) Parallel linkage [1]. 1 5(b) Explanation should include: 2 Explanation with two points made, [2]. Allow 2 marks for a single fully justified • As the bucket / container moves up it will stay parallel to the ground point. • Any liquid contents will not spill out. • Solids being lifted will not tip. • Increased visibility for truck operator. 5(c) Types of linkage shown could include: 2 Allow any recognised form of linkage apart from parallel motion. • Crank and slider • Crank and piston • Bell crank linkage • ‘Z’ bar linkage Clear sketch [1] notes to indicate how it works [1]

This question in 0445/43 Oct/Nov 2023

6 Fig. 6.1 shows a simplified line drawing of a small internal combustion (IC) engine. cylinder piston crankshaft Fig. 6.1 State the conversion of motion that takes place in the IC engine when the crankshaft is driven by the piston. … to … [2]

2 marks

Mark scheme: 6 Reciprocating motion [1] is converted to rotary motion [1] 2

This question in 0445/43 Oct/Nov 2023

10 (a) Fig. 10.1 shows a cam and follower mechanism. spring nylon bearing cam follower cam position Fig. 10.1 (i) Draw a cam on the position shown in Fig. 10.1 to operate the cam follower 4 times for each revolution of the cam. [2] (ii) State the purpose of the spring. … [1] (iii) The bearing supporting the follower is made from nylon. Give two properties of nylon that make it a suitable material for the bearing. 1 … … 2 … … [2] (b) Fig. 10.2 shows a toy gyroscope used to demonstrate how a spinning rotor can be used to stabilise motion. The rotor is made to spin by pulling on a string that is wrapped around the axle. hole for string plain bearing rotor string is used to spin the rotor axle plain bearing Fig. 10.2 (i) State the conversion of motion that takes place when the string is pulled. … to … [2] (ii) The axle is supported at each end by plain bearings. Explain what is meant by a plain bearing. … … … … [2] (iii) State two factors that will affect the length of time that the rotor will spin. 1 … … 2 … … [2] (c) Fig. 10.3 shows details of a vee belt and a flat belt that can drive a pulley in either direction. vee belt flat belt Fig. 10.3 (i) Give two advantages that the vee belt has when being used to drive a pulley on a machine. 1 … … 2 … … [2] (ii) Sketch the arrangement of the flat belt that will change the direction of the driven pulley. [1] (iii) Explain why the vee belt cannot change the direction of the driven pulley. … … … … [2] (iv) Use sketches and notes to show a method of tensioning a vee belt without changing the position of the pulleys. [3] (d) Fig. 10.4 shows a section through a car jack. 250 thread pitch 1.75 mm Fig. 10.4 (i) Calculate the velocity ratio (VR) of the car jack. … … … … [2] (ii) The car jack is 30% efficient. Give one reason for the loss of efficiency in the car jack. … … [1] (iii) Calculate the effort needed to lift a load of 5 kN, ignoring the loss of efficiency. … … … … [3]

25 marks

Mark scheme: 10(a)(i) 2 Square cam drawn [1] suitable proportions [1] 10(a)(ii) The spring ensures that the follower is always touching the cam. 1 Allow mark for understanding shown. 10(a)(iii) Mechanical property of nylon: 2 Do not accept cost related properties • Efficient bearing material • Self-lubricating • Does not corrode / durable • Ease of batch production – can be moulded Electrical property: • It is an insulator. [2  1] 10(b)(i) Linear motion is converted to rotary motion 2 10(b)(ii) Plain bearings: 2 1 mark for each point mentioned in explanation, up to 2 marks. • Are a plain surface • Reduces friction • With no rolling elements • They allow rotation between two parts 10(b)(iii) Factors will include: 2 Allow other valid points. • Adjustment of the plain bearing • Any additional lubrication added to bearing surfaces • Speed with which the string is pulled • Length of string wrapped around the spindle • Diameter / mass of rotor. [2  1] 10(c)(i) Advantages of the vee belt include: 2 Allow other valid advantages • Larger section so less likely to stretch • Vee belt will provide more grip when it is pulled into the vee of the pulley • Less likely to slip than a flat belt • Precise torque transfer between pulleys • Durable • Quieter when operating. [2  1] 10(c)(ii) Flat belt will be crossed over to reverse direction 1 10(c)(iii) Explanation to include: 2 Award marks for understanding shown in explanation. The thickness of the vee belt does not allow it to bend backwards [1] The outer surface of the vee would be next to the pulley [1] 10(c)(iv) Sketches and notes to indicate: 3 • Idler wheel pressed against the vee belt [1] • Method of adjusting the idler wheel [1] • Position of two pulleys is not altered [1] 10(d)(i) Distance moved by thread in 1 revolution = 1.75 mm 2 Allow rounding errors in calculation. Distance moved by handle =   2  250 = 1571 [1] VR = 1571 / 1.75 = 897.6, [1] 10(d)(ii) Loss of efficiency will be due to: 1 Allow mark for understanding shown. • Friction in the jack components • Heat • Sound 10(d)(iii) Effort = load / VR [1] 3 Allow ecf from (d)(i) = 5000 / 897.6 [1] = 5.57 N [1] Alternative method – (load  pitch) / effort distance [1] = (5000  .00175) ( x 2  250) [1] = 5.57 N [1]

This question in 0445/43 Oct/Nov 2023

3 Fig. 3.1 shows a lever being used to move a link rod that is attached to a second lever. lever L1 X Y lever L2 Z fixed pivot points Fig. 3.1 (a) State the class of levers L1 and L2. L1 … L2 … [2] (b) Add arrows to Fig. 3.1 to show how link rods Y and Z will move when lever L1 rotates in direction X. [2]

4 marks

Mark scheme: 3(a) L1 is a second class lever, L2 is a first class lever [21] 2 3(b) [21] 2

This question in 0445/41 May/June 2024

4 Oil or grease can be used to reduce friction in a moving joint. Give two benefits of reducing friction in a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 4 Any two benefits such as:  Reduced wear on parts / mechanism last longer  Reduced sound  Reduced heat in mechanism  Increased efficiency [21]

This question in 0445/41 May/June 2024

5 Give two reasons for using spur gears in a mechanism. 1 … … 2 … … [2]

2 marks

Mark scheme: 5 Spur gears in a mechanism are used to:  transfer motion between shafts  increase / decrease speed of output  change direction of motion  provide a connection that cannot slip. [21] Do not allow cost related reasons

This question in 0445/41 May/June 2024

11 (a) Fig. 11.1 shows a piece of exercise equipment in a park. The equipment uses feet and hands to operate it. Fig. 11.1 (i) From the list below, give the name of the mechanism that is used to convert motion in the exercise equipment. rack and pinion crank and linkage ratchet and pawl … [1] (ii) State the conversion of motion that takes place when the equipment is used. … to … [2] (iii) Fig. 11.2 shows where grease is applied to lubricate the moving parts on a different piece of exercise equipment. Fig. 11.2 Explain why grease is used rather than oil to lubricate the equipment. … … … … [2] (b) Table 11.1 lists four different types of wheel. Table 11.1 Bearing type Type of wheel plain roller ball train skateboard wheelbarrow cycle (i) Tick (3) the most suitable type of bearing for each wheel. [4] (ii) Describe the factors that must be considered when choosing bearings for a particular use. … … … … [3] (c) Fig. 11.3 shows an eccentric mechanism and a cam and follower. eccentric cam centre of rotation centre of follower follower guide pin rotation compression spring guide for cam follower Fig. 11.3 (i) Describe the difference between the two mechanisms in terms of rise, fall and dwell. … … … [2] (ii) Give one benefit of the eccentric mechanism shown in Fig. 11.3. … [1] (iii) State two ways that efficiency can be lost in a mechanism. 1 … 2 … [2] (d) Fig. 11.4 shows a gear arrangement. 10t driver gear 30t 32t 36t driven gear 16t 10t Fig. 11.4 Calculate the speed of the driven gear when the driver gear is rotating at 864 rpm. … … … … [3] (e) Levers and links are commonly used in mechanisms. (i) A bell crank lever is used to change the direction of force through 90°. Use sketches and notes to show a bell crank lever connecting the two links shown. link B link A [2] (ii) Fig. 11.5 shows a threaded bolt that could be used to connect two links together. State the meaning of the label M10 × 1.5. Fig. 11.5 M10 … 1.5 … [2] (iii) State the rotational force that is applied to the body of the bolt when a spanner is used to tighten it. … … [1]

25 marks

Mark scheme: 11(a)(i) The mechanism is a crank and linkage [1] 1 11(a)(ii) Rotary [1] to oscillating [1] 2 Allow reciprocating for the output motion. 11(a)(iii) Grease is used on the joint because:  it will not run out of the joint  it will last a long time  not so affected by temperature change  easier to apply to the joint than oil. 2 Explanation with two points = 2 marks. Allow 2 marks for a single point fully justified. 11(b)(i) [41] 4 Award no marks for each row with multiple ticks 11(b)(ii) Factors for choice will include:  Speed of rotation / movement  Materials involved  Likely radial or axial loading  Cost of bearing  Ease of replacement [31] 3 Accept any other valid factors. 1 mark per valid factor in the description. Allow 2 marks for a clear, fully justified description of a single point. 11(c)(i) The eccentric will constantly be rising and falling during a single rotation [1] The cam has 180º of dwell every rotation [1] 2 Description must include these two points for both marks. 11(c)(ii) The eccentric is driven in both directions, rising and falling, the cam relies on a spring to maintain contact between cam and follower 1 Allow mark for understanding shown. Question Answer Marks Guidance 11(c)(iii) Efficiency can be lost through:  Friction in a mechanism  Lack of lubrication  Conversion to unwanted energy forms, heat or sound  Worn parts in the mechanism [21] 2 Allow ‘lack of lubrication’ Accept any other valid response. 11(d) 10t30t gear has a ratio of 3:1 16t32t gear has a ratio of 2:1 10t36t gear has a ratio of 3.6:1 Calculation of individual reductions [1] Overall reduction ratio is 3  2  3.6 = 21.6:1 [1] Speed of driven gear = 864 / 21.6 = 40 rpm. [1] 3 Award 3 marks for correct speed of driven gear with no working. 11(e)(i) Bell crank lever with a fixed pivot point [1] Connected to two links at 90º to each other [1] 2 11(e)(ii) M10 means that the bolt has a diameter of 10mm [1] 1.5 refers to the pitch of the thread [1] 2 11(e)(iii) A spanner will apply torque [1] to the body of the bolt when it is used on the hexagonal head 1 Allow ‘torsion’

This question in 0445/41 May/June 2024

4 Use sketches and notes to show one example of a first order lever and one example of a third order lever. Use the space provided above each label. first order lever third order lever [2]

2 marks

Mark scheme: 4 1 mark for each correct example First order = L F E third order = F E L 2 Examples must be above correct label.

This question in 0445/42 May/June 2024

5 Fig. 5.1 shows three different arrangements of spur gears. driven driven driver driven driver driver A B C Fig. 5.1 State the change in output at the driven gear for each arrangement. A … B … C … [3]

3 marks

Mark scheme: 5 A – Same speed for driver and driven or opposite direction [1] B – Driven gear will be slower or rotating in opposite direction with increased torque [1] C – Same speed for both gears or they will rotate in same direction [1] arrangement.

This question in 0445/42 May/June 2024

6 Fig. 6.1 shows an electric scooter. motor casing Fig. 6.1 Give the conversion of motion that occurs when the motor operates, and the scooter starts to move. … motion to … motion. [2]

2 marks

Mark scheme: 6 Input motion is rotary [1] Output motion is linear [1] 2

This question in 0445/42 May/June 2024

11 (a) Fig. 11.1 shows a gardening tool used for cutting branches from trees. It uses a lever combined with a gear mechanism to provide the cutting force. larger gear smaller gear lever A lever A Fig. 11.1 (i) Add the letters ‘L’ ‘F’ and ‘E’ to the correct circles to show the position of the load (L), fulcrum (F) and effort (E) for lever A. [3] (ii) Explain how the gear mechanism reduces the effort needed to operate the gardening tool when cutting a branch. … … … … [3] (iii) Give one reason for loss of efficiency when using the gardening tool. … … [1] (b) Using examples, describe why the following types of gear would be used. (i) Bevel gears … … … [2] (ii) Worm gear … … … [2] (iii) Rack and pinion gears … … … [2] (c) Fig. 11.2 shows the drive system on a lawnmower. The drive uses toothed and vee belt pulley systems to reduce the speed of rotation provided by the electric motor. toothed belt motor drive casing lawnmower vee belt Fig. 11.2 (i) Give one reason for using a toothed belt rather than a flat belt for the drive from the motor. … … [1] (ii) The final drive to the cutting blades is provided by a vee belt. Explain how the use of a vee belt could prevent damage to the motor. … … … [2] (iii) Fig. 11.3 shows the method of tensioning the vee belt. tensioning pulley adjustment slot Fig. 11.3 Give two reasons why adjustment to the tension of the vee belt may be needed. 1 … … 2 … … [2] (iv) Fig. 11.4 shows the belt and pulley system between the motor and the final drive. Calculate the speed of rotation of the final drive when the motor turns at 1000 rpm. Ø75 Ø50 motor tensioning pulley Ø100 Ø12.5 final drive Fig. 11.4 … … … … [4] (d) (i) State what is meant by the ‘pitch’ of a screw thread on a bolt. … … … [1] (ii) Give two ways, apart from pitch, that can be used to specify a screw thread on a bolt. 1 … 2 … [2]

25 marks

Mark scheme: 11(a)(i) 1 mark for load identified, 1 mark for fulcrum identified, 1 mark for effort identified 3 11(a)(ii) The use of gear mechanism will reduce effort / small to larger gear [1] The lever effect of the long handle is multiplied [1] by the gear ratio [1] to give overall reduced effort 2 1 mark for each valid point. Award 2 marks for a single point fully explained. 11(a)(iii) Lost efficiency will be due to friction in the mechanism. 1 11(b)(i) Bevel gears are used where the input and output are in different orientations normally 90 to each other [1] VR needs altering [1] e.g. Drill chuck key [1] [2  1] 2 Accept any other valid response 11(b)(ii) A worm gear will give a large reduction in speed [1] cannot rotate in reverse [1] so provides a self-locking facility [1] e.g. winch, elevator motor drive [1] small space used [1] [2  1, any two points made] 2 Accept any other valid response, e.g. changing axes of rotation by 90 Question Answer Marks Guidance 11(b)(iii) Rack and pinion gears are used to convert rotary motion into linear or reciprocating motion [1], e.g. car steering, drill table rise and fall [1] 2 Accept any other valid response, e.g. lifting mechanisms, positioning mechanisms. 11(c)(i) A toothed belt will not slip, it is possible to keep pulleys in the same relative positions. 1 11(c)(ii) The vee belt will allow slipping [1] if the blades get jammed [1] 2 11(c)(iii) Tension of the vee belt may need adjusting:  To allow a new belt to be fitted.  To prevent slipping on the pulleys  To compensate for wear in the belt as it stretches.  To prevent wear in the belt. [2  1] 2 Accept any other valid reasons. 11(c)(iv) Reduction from motor to intermediate pulley is 6:1 [1] Reduction from intermediate pulley to final drive is 2:1 [1] Total reduction is 12:1[1] Final speed = 83.3 rpm [1] 4 Award 4 marks for correct answer with no working. 11(d)(i) The pitch of a thread is:  The distance that it moves in for each rotation  or  It is measured from the top of one thread to the top of the next 1 Allow mark for understanding shown. 11(d)(ii) The following methods can be used to specify a screw thread: length, diameter, material, finish, head shape [2  1] 2 Allow different thread profiles, e.g. acme, square, LH thread.

This question in 0445/42 May/June 2024

3 Fig. 3.1 shows a lever being used to move a link rod that is attached to a second lever. lever L1 X Y lever L2 Z fixed pivot points Fig. 3.1 (a) State the class of levers L1 and L2. L1 … L2 … [2] (b) Add arrows to Fig. 3.1 to show how link rods Y and Z will move when lever L1 rotates in direction X. [2]

4 marks

Mark scheme: 3(a) L1 is a second class lever, L2 is a first class lever [2  1] 2 3(b) [2  1] 2

This question in 0445/43 May/June 2024

4 Oil or grease can be used to reduce friction in a moving joint. Give two benefits of reducing friction in a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 4 Benefits will include:  Reduced wear on parts / mechanism last longer  Reduced sound  Reduced heat in mechanism  Increased efficiency [2  1]

This question in 0445/43 May/June 2024

5 Give two reasons for using spur gears in a mechanism. 1 … … 2 … … [2]

2 marks

Mark scheme: 5 Spur gears in a mechanism are used to:  transfer motion between shafts  increase / decrease speed of output  change direction of motion  provide a connection that cannot slip. [2  1] Do not allow cost related reasons

This question in 0445/43 May/June 2024

11 (a) Fig. 11.1 shows a piece of exercise equipment in a park. The equipment uses feet and hands to operate it. Fig. 11.1 (i) From the list below, give the name of the mechanism that is used to convert motion in the exercise equipment. rack and pinion crank and linkage ratchet and pawl … [1] (ii) State the conversion of motion that takes place when the equipment is used. … to … [2] (iii) Fig. 11.2 shows where grease is applied to lubricate the moving parts on a different piece of exercise equipment. Fig. 11.2 Explain why grease is used rather than oil to lubricate the equipment. … … … … [2] (b) Table 11.1 lists four different types of wheel. Table 11.1 Bearing type Type of wheel plain roller ball train skateboard wheelbarrow cycle (i) Tick (3) the most suitable type of bearing for each wheel. [4] (ii) Describe the factors that must be considered when choosing bearings for a particular use. … … … … [3] (c) Fig. 11.3 shows an eccentric mechanism and a cam and follower. eccentric cam centre of rotation centre of follower follower guide pin rotation compression spring guide for cam follower Fig. 11.3 (i) Describe the difference between the two mechanisms in terms of rise, fall and dwell. … … … [2] (ii) Give one benefit of the eccentric mechanism shown in Fig. 11.3. … [1] (iii) State two ways that efficiency can be lost in a mechanism. 1 … 2 … [2] (d) Fig. 11.4 shows a gear arrangement. 10t driver gear 30t 32t 36t driven gear 16t 10t Fig. 11.4 Calculate the speed of the driven gear when the driver gear is rotating at 864 rpm. … … … … [3] (e) Levers and links are commonly used in mechanisms. (i) A bell crank lever is used to change the direction of force through 90°. Use sketches and notes to show a bell crank lever connecting the two links shown. link B link A [2] (ii) Fig. 11.5 shows a threaded bolt that could be used to connect two links together. State the meaning of the label M10 × 1.5. Fig. 11.5 M10 … 1.5 … [2] (iii) State the rotational force that is applied to the body of the bolt when a spanner is used to tighten it. … … [1]

25 marks

Mark scheme: 11(a)(i) The mechanism is a crank and linkage [1] 1 11(a)(ii) Rotary [1] to oscillating [1] 2 Allow reciprocating for the output motion. 11(a)(iii) Grease is used on the joint because:  it will not run out of the joint  it will last a long time  not so affected by temperature change  easier to apply to the joint than oil. 2 Explanation with two points = 2 marks. Allow 2 marks for a single point fully justified. 11(b)(i) [4  1] 4 Award no marks for each row with multiple ticks 11(b)(ii) Factors for choice will include:  Speed of rotation / movement  Materials involved  Likely radial or axial loading  Cost of bearing  Ease of replacement [3  1] 3 Accept any other valid factors. 1 mark per valid factor in the description. Allow 2 marks for a clear, fully justified description of a single point. 11(c)(i) The eccentric will constantly be rising and falling during a single rotation [1] The cam has 180º of dwell every rotation [1] 2 Description must include these two points for both marks. 11(c)(ii) The eccentric is driven in both directions, rising and falling, the cam relies on a spring to maintain contact between cam and follower 1 Allow mark for understanding shown. Question Answer Marks Guidance 11(c)(iii) Efficiency can be lost through:  Friction in a mechanism  Lack of lubrication  Conversion to unwanted energy forms, heat or sound  Worn parts in the mechanism [2  1] 2 Allow ‘lack of lubrication’ Accept any other valid response. 11(d) 10t30t gear has a ratio of 3:1 16t32t gear has a ratio of 2:1 10t36t gear has a ratio of 3.6:1 Calculation of individual reductions [1] Overall reduction ratio is 3  2  3.6 = 21.6:1 [1] Speed of driven gear = 864 / 21.6 = 40 rpm. [1] 3 Award 3 marks for correct speed of driven gear with no working. 11(e)(i) Bell crank lever with a fixed pivot point [1] Connected to two links at 90º to each other [1] 2 11(e)(ii) M10 means that the bolt has a diameter of 10mm [1] 1.5 refers to the pitch of the thread [1] 2 11(e)(iii) A spanner will apply torque [1] to the body of the bolt when it is used on the hexagonal head 1 Allow ‘torsion’

This question in 0445/43 May/June 2024

12 (a) Fig. 12.1 shows a rectangular LED that will be used to show the logic level of a NAND gate output. Fig. 12.1 (i) State one way of identifying the negative leg (cathode) of the LED. … … [1] (ii) Fig. 12.2 shows a test circuit for the LED. +9 V 47 kΩ 0 V Fig. 12.2 Explain why the LED does not appear to light up when the circuit is tested. … … … [2] (iii) The LED has a voltage drop of 1.75 V and the supply to the circuit is +9 V. Calculate the value of resistor that will limit the current passing through the LED to 15 mA. V Use the formula: I = R … … … … [3] (b) Fig. 12.3 shows the outline of a CMOS 4001 quad NOR gate IC, with the internal connections to the logic gates shown. 4001B Fig. 12.3 (i) Add pin numbers to the IC outline in Fig. 12.3. [2] (ii) Add the positive and 0 V connections to the IC outline in Fig. 12.3. [1] (iii) State the logic function that will result from connecting the two inputs of one of the logic gates. … [1] (iv) Fig. 12.4 shows a circuit diagram for a PTM switch that could be used to provide a logic signal to one of the inputs of the NOR gate IC. signal to NOR gate input R1 Fig. 12.4 Explain why Resistor R1 is necessary. … … … … [2] (c) (i) State how the direction of rotation of a DC motor can be reversed. … … [1] (ii) Fig. 12.5 shows a circuit diagram with a DPDT relay and a motor. The relay is operated by a transistor switch. Add connections to the relay contacts that will allow the motor to be reversed. +5 V +12 V D1 input signal M 0 V Fig. 12.5 [3]

16 marks

Mark scheme: 12(a)(i) The negative leg (cathode) can be identified by:  Negative leg is shorter than the positive leg  Use of a diode tester on a multimeter  Trial and error in a breadboard 1 1 mark for a functional method 12(a)(ii) By using a high value protective resistor there will be a very low current passing through the LED [1] This is not enough to allow it to light up [1] 2 Allow marks for understanding shown. 12(a)(iii) Use of voltage drop, +9 V – 1.75 V = 7.25 V [1] Use of formula I = V/R rearranged to R = V/I [1] 7.25 / 0.015 = 483.3 Ω [1] 3 Allow rounding errors 12(b)(i) Pins 0 – 7 correctly numbered [1] Pins 8 – 14 correctly numbered [1] 2 12(b)(ii) Positive labelled at pin 14 and 0V at pin 7 [1] 1 12(b)(iii) Connecting two inputs to the same gate makes a NOT gate or inverter [1] 1 12(b)(iv) R1 is a pull down resistor used to ensure that the signal to the NOR gate always has a logic level [1] The NOR gate will not operate reliably if an input is at a floating level [1] 2 Question Answer Marks Guidance 12(c)(i) The direction of a DC motor can be reversed by changing polarity of the inputs [1] 1 Allow mark for understanding shown. 12(c)(ii) +12 V to a relay common, 0 V to other relay common [1] Both poles of relay normally open to normally closed connected [1] Motor connections, one to positive, one to 0 V [1] 3 12(c)(iii) The diode is in the circuit to protect the transistor [1] from reverse emf [1] 2 Allow marks for understanding shown 12(d)(i) The layout is designed from the top looking down on the PCB [1] Artwork must have circuit and writing reversed (mirrored) to transfer correctly to the PCB conducting layer [1] 2 12(d)(ii) Wires shown secured into terminal block [1] Securing method could be small clamp, two holes to thread wires through or similar [1] No damage caused to track areas of PCB [1] 3 12(e) The two components are capacitor [1] and potentiometer [1] 2

This question in 0445/43 May/June 2024

4 Fig. 4.1 shows a car handbrake lever. X handbrake cable Fig. 4.1 (a) Describe how friction in the pivot at point X can be reduced. … … … [2] (b) State why the handbrake lever is described as a first class lever. … [1] (c) The handbrake lever converts oscillating motion to reciprocating motion. Name the two other types of motion. 1 … 2 … [2]

5 marks

Mark scheme: 4(a) Friction can be reduced by: use of good bearing materials , lubricating moving 2 1 mark for each point mentioned. parts with oil or grease, reduction of areas in contact [2  1] Allow reference to specified bearing types. Allow 2 marks for a single point fully described. 4(b) The fulcrum (pivot at point X) is between the effort and load 1 4(c) Linear motion [1] 2 Rotary motion [1]

This question in 0445/41 Oct/Nov 2024

5 Give two reasons for choosing spur gears to drive a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 5 Reasons for choosing spur gears will include: they are positive method of 2 AOVR connecting shafts, no slipping is possible, efficient method, reduction or Reference to ‘high loads’ = BOD mark. increase in output speed is possible, direction of motion can be changed No mark for ‘ease of availability’ or ‘cost’ easily, increased torque if a reduction ratio is used [2  1]

This question in 0445/41 Oct/Nov 2024

6 Fig. 6.1 shows two spur gears. drive gear A driven gear B Fig. 6.1 State two effects of using the spur gears shown in Fig. 6.1. 1 … 2 … [2]

2 marks

Mark scheme: 6 The driven gear will be rotating faster than the drive gear [1] 2 Do not award no more than 2 marks The direction of rotation will be changed [1] Torque will be reduced [1] [2  1]

This question in 0445/41 Oct/Nov 2024

10 (a) Fig. 10.1 shows a mechanism used to raise or lower a gate on a waterway. square taper Y X shaft Fig. 10.1 (i) State the names of parts X and Y that are used in the mechanism. X … Y … [2] (ii) Describe how the mechanism in Fig. 10.1 controls rotation of the shaft. … … … … [3] (iii) Fig. 10.2 shows a cranked handle that can be fitted to the square taper on the end of the shaft allowing the shaft to be turned. tapered square hole Fig. 10.2 Give one benefit of using this method of fitting the handle. … … [1] (iv) Explain what is meant by mechanical advantage in a mechanism. … … … … [2] (v) Use sketches and notes to show how the mechanical advantage and efficiency of the cranked handle in Fig. 10.2 could be increased. [3] (b) Fig. 10.3 shows a small circular saw and the method used to mount the motor. motor 4 slots for mounting motor 4 threaded bolt holes Fig. 10.3 (i) Give two reasons for using four slots to mount the motor. 1 … … 2 … … [2] (ii) Use sketches and notes to show how the vee belt used to drive the circular saw can be tensioned. [2] (iii) Fig. 10.4 shows the belt and pulley arrangement between the motor and the saw blade. cover on lubrication hole motor pulley Ø64 saw blade pulley Ø46 Fig. 10.4 The motor has a rotational speed of 2850 rpm when not under load. Calculate the rotational speed of the saw blade when the motor is switched on. … … … … [3] (iv) Explain why the actual rotational speed in use may be less than the calculated speed. … … … [2] (v) Give one reason for having covers over the lubrication holes at each end of the motor. … … [1] (c) (i) State what is meant by a plain bearing. … … [1] (ii) Fig. 10.5 shows a tapered roller bearing with a section showing a wheel hub and axle that uses tapered roller bearings. tapered rollers inner race outer race wheel hub outer race axle tapered rollers adjustment nut inner race Fig. 10.5 Explain why tapered roller bearings are used in pairs with the tapered ends of the rollers facing each other on the axle. … … … … [3]

25 marks

Mark scheme: 10(a)(i) X is a ratchet [1] 2 Do not allow reverse answers. Y is a pawl [1] 10(a)(ii) Description to include: shaft can only rotate in one direction, ratchet rotates 3 1 mark for each valid point up to maximum with the shaft, pawl is free to oscillate, engages with ratchet using gravity to 3. drop, shaft is prevented from turning backwards by pawl. Allow 2 marks for a single point fully justified. 10(a)(iii) Benefits of tapered shaft include: can always fit tightly onto shaft, no method of 1 Allow other valid reasons locking in place is required, can be easily removed from the shaft, square on shaft gives is a positive method that does not allow any slipping 10(a)(iv) Mechanical advantage is a measure of advantage gained [1] 2 Award marks for understanding shown. by using a mechanism to transmit force [1] 10(a)(v) Sketch or notes showing an increase in distance between centre of shaft and 3 centre of handle [1] Notes showing understanding of how advantage is increased [1] Method of reducing friction between the hand grip and hand of the user [1] 10(b)(i) Reasons could include: four holes provide a stable method of mounting, the 2 Allow other valid reasons load is spread over a greater surface area than if using only two holes, slots allow for positioning and tensioning of the motor [2  1] 10(b)(ii) Methods used could include: a lever to force the motor back, tensioning the 2 1 mark for each valid point included in belt, bolts tightened gradually while motor is held in position, check made on sketches or notes. tension of belt before fully tightening the bolts, a spring operated idler pulley Valid principle used [1] clear notes / sketches [1] 10(b)(iii) Motor pulley / saw blade pulley = 64 / 46 = 1.391 [1] 3 Correct answer with no working = 3 marks 1.391  motor speed 2850 rpm [1] Allow rounding differences. = 3965 rpm [1] 10(b)(iv) Explanation to include: frictional losses, heat and sound produced when 2 1 mark for each valid point, maximum 2. cutting, size and weight of blade, pressure of wood on blade, Allow 2 marks for a single point fully poor / inadequate lubrication, slipping belt on pulley [2 1] explained. 10(b)(v) The covers will prevent dust, sawdust etc from entering the lubrication hole 1 and being drawn into the bearings 10(c)(i) A plain bearing is a simple bearing with no moving parts. 1 It will normally be made of a material that has friction reducing properties. Material will be softer than the shaft that is running in it. 10(c)(ii) Using tapered roller bearings in pairs allows: adjustment of the bearings, both 3 AOVR radial and axial/thrust loading can be controlled, heavy loads to be supported, 1 mark for each point included up to three. support over an increased axle distance, easy lubrication with grease Allow 2 marks for a single point described in depth.

This question in 0445/41 Oct/Nov 2024

4 Fig. 4.1 shows a car handbrake lever. X handbrake cable Fig. 4.1 (a) Describe how friction in the pivot at point X can be reduced. … … … [2] (b) State why the handbrake lever is described as a first class lever. … [1] (c) The handbrake lever converts oscillating motion to reciprocating motion. Name the two other types of motion. 1 … 2 … [2]

5 marks

Mark scheme: 4(a) Friction can be reduced by: use of good bearing materials , lubricating moving 2 1 mark for each point mentioned. parts with oil or grease, reduction of areas in contact [2  1] Allow reference to specified bearing types. Allow 2 marks for a single point fully described. 4(b) The fulcrum (pivot at point X) is between the effort and load 1 4(c) Linear motion [1] 2 Rotary motion [1]

This question in 0445/42 Oct/Nov 2024

5 Give two reasons for choosing spur gears to drive a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 5 Reasons for choosing spur gears will include: they are positive method of 2 AOVR connecting shafts, no slipping is possible, efficient method, reduction or Reference to ‘high loads’ = BOD mark. increase in output speed is possible, direction of motion can be changed No mark for ‘ease of availability’ or ‘cost’ easily, increased torque if a reduction ratio is used [2  1]

This question in 0445/42 Oct/Nov 2024

6 Fig. 6.1 shows two spur gears. drive gear A driven gear B Fig. 6.1 State two effects of using the spur gears shown in Fig. 6.1. 1 … 2 … [2]

2 marks

Mark scheme: 6 The driven gear will be rotating faster than the drive gear [1] 2 Do not award no more than 2 marks The direction of rotation will be changed [1] Torque will be reduced [1] [2  1]

This question in 0445/42 Oct/Nov 2024

10 (a) Fig. 10.1 shows a mechanism used to raise or lower a gate on a waterway. square taper Y X shaft Fig. 10.1 (i) State the names of parts X and Y that are used in the mechanism. X … Y … [2] (ii) Describe how the mechanism in Fig. 10.1 controls rotation of the shaft. … … … … [3] (iii) Fig. 10.2 shows a cranked handle that can be fitted to the square taper on the end of the shaft allowing the shaft to be turned. tapered square hole Fig. 10.2 Give one benefit of using this method of fitting the handle. … … [1] (iv) Explain what is meant by mechanical advantage in a mechanism. … … … … [2] (v) Use sketches and notes to show how the mechanical advantage and efficiency of the cranked handle in Fig. 10.2 could be increased. [3] (b) Fig. 10.3 shows a small circular saw and the method used to mount the motor. motor 4 slots for mounting motor 4 threaded bolt holes Fig. 10.3 (i) Give two reasons for using four slots to mount the motor. 1 … … 2 … … [2] (ii) Use sketches and notes to show how the vee belt used to drive the circular saw can be tensioned. [2] (iii) Fig. 10.4 shows the belt and pulley arrangement between the motor and the saw blade. cover on lubrication hole motor pulley Ø64 saw blade pulley Ø46 Fig. 10.4 The motor has a rotational speed of 2850 rpm when not under load. Calculate the rotational speed of the saw blade when the motor is switched on. … … … … [3] (iv) Explain why the actual rotational speed in use may be less than the calculated speed. … … … [2] (v) Give one reason for having covers over the lubrication holes at each end of the motor. … … [1] (c) (i) State what is meant by a plain bearing. … … [1] (ii) Fig. 10.5 shows a tapered roller bearing with a section showing a wheel hub and axle that uses tapered roller bearings. tapered rollers inner race outer race wheel hub outer race axle tapered rollers adjustment nut inner race Fig. 10.5 Explain why tapered roller bearings are used in pairs with the tapered ends of the rollers facing each other on the axle. … … … … [3]

25 marks

Mark scheme: 10(a)(i) X is a ratchet [1] 2 Do not allow reverse answers. Y is a pawl [1] 10(a)(ii) Description to include: shaft can only rotate in one direction, ratchet rotates 3 1 mark for each valid point up to maximum with the shaft, pawl is free to oscillate, engages with ratchet using gravity to 3. drop, shaft is prevented from turning backwards by pawl. Allow 2 marks for a single point fully justified. 10(a)(iii) Benefits of tapered shaft include: can always fit tightly onto shaft, no method of 1 Allow other valid reasons locking in place is required, can be easily removed from the shaft, square on shaft gives is a positive method that does not allow any slipping 10(a)(iv) Mechanical advantage is a measure of advantage gained [1] 2 Award marks for understanding shown. by using a mechanism to transmit force [1] 10(a)(v) Sketch or notes showing an increase in distance between centre of shaft and 3 centre of handle [1] Notes showing understanding of how advantage is increased [1] Method of reducing friction between the hand grip and hand of the user [1] 10(b)(i) Reasons could include: four holes provide a stable method of mounting, the 2 Allow other valid reasons load is spread over a greater surface area than if using only two holes, slots allow for positioning and tensioning of the motor [2  1] 10(b)(ii) Methods used could include: a lever to force the motor back, tensioning the 2 1 mark for each valid point included in belt, bolts tightened gradually while motor is held in position, check made on sketches or notes. tension of belt before fully tightening the bolts, a spring operated idler pulley Valid principle used [1] clear notes / sketches [1] 10(b)(iii) Motor pulley / saw blade pulley = 64 / 46 = 1.391 [1] 3 Correct answer with no working = 3 marks 1.391  motor speed 2850 rpm [1] Allow rounding differences. = 3965 rpm [1] 10(b)(iv) Explanation to include: frictional losses, heat and sound produced when 2 1 mark for each valid point, maximum 2. cutting, size and weight of blade, pressure of wood on blade, Allow 2 marks for a single point fully poor / inadequate lubrication, slipping belt on pulley [2 1] explained. 10(b)(v) The covers will prevent dust, sawdust etc from entering the lubrication hole 1 and being drawn into the bearings 10(c)(i) A plain bearing is a simple bearing with no moving parts. 1 It will normally be made of a material that has friction reducing properties. Material will be softer than the shaft that is running in it. 10(c)(ii) Using tapered roller bearings in pairs allows: adjustment of the bearings, both 3 AOVR radial and axial/thrust loading can be controlled, heavy loads to be supported, 1 mark for each point included up to three. support over an increased axle distance, easy lubrication with grease Allow 2 marks for a single point described in depth.

This question in 0445/42 Oct/Nov 2024

4 Fig. 4.1 shows a car handbrake lever. X handbrake cable Fig. 4.1 (a) Describe how friction in the pivot at point X can be reduced. … … … [2] (b) State why the handbrake lever is described as a first class lever. … [1] (c) The handbrake lever converts oscillating motion to reciprocating motion. Name the two other types of motion. 1 … 2 … [2]

5 marks

Mark scheme: 4(a) Friction can be reduced by: use of good bearing materials, lubricating moving 2 1 mark for each point mentioned. parts with oil or grease, reduction of areas in contact [2  1] Allow reference to specified bearing types. Allow 2 marks for a single point fully described. 4(b) The fulcrum (pivot at point X) is between the effort and load 1 4(c) Linear motion [1] 2 Rotary motion [1]

This question in 0445/43 Oct/Nov 2024

5 Give two reasons for choosing spur gears to drive a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 5 Reasons for choosing spur gears will include: they are positive method of 2 AOVR connecting shafts, no slipping is possible, efficient method, reduction or Reference to ‘high loads’ = BOD mark. increase in output speed is possible, direction of motion can be changed No mark for ‘ease of availability’ or ‘cost’ easily, increased torque if a reduction ratio is used [2  1]

This question in 0445/43 Oct/Nov 2024

6 Fig. 6.1 shows two spur gears. drive gear A driven gear B Fig. 6.1 State two effects of using the spur gears shown in Fig. 6.1. 1 … 2 … [2]

2 marks

Mark scheme: 6 The driven gear will be rotating faster than the drive gear [1] 2 Do not award no more than 2 marks The direction of rotation will be changed [1] Torque will be reduced [1] [2  1]

This question in 0445/43 Oct/Nov 2024

10 (a) Fig. 10.1 shows a mechanism used to raise or lower a gate on a waterway. square taper Y X shaft Fig. 10.1 (i) State the names of parts X and Y that are used in the mechanism. X … Y … [2] (ii) Describe how the mechanism in Fig. 10.1 controls rotation of the shaft. … … … … [3] (iii) Fig. 10.2 shows a cranked handle that can be fitted to the square taper on the end of the shaft allowing the shaft to be turned. tapered square hole Fig. 10.2 Give one benefit of using this method of fitting the handle. … … [1] (iv) Explain what is meant by mechanical advantage in a mechanism. … … … … [2] (v) Use sketches and notes to show how the mechanical advantage and efficiency of the cranked handle in Fig. 10.2 could be increased. [3] (b) Fig. 10.3 shows a small circular saw and the method used to mount the motor. motor 4 slots for mounting motor 4 threaded bolt holes Fig. 10.3 (i) Give two reasons for using four slots to mount the motor. 1 … … 2 … … [2] (ii) Use sketches and notes to show how the vee belt used to drive the circular saw can be tensioned. [2] (iii) Fig. 10.4 shows the belt and pulley arrangement between the motor and the saw blade. cover on lubrication hole motor pulley Ø64 saw blade pulley Ø46 Fig. 10.4 The motor has a rotational speed of 2850 rpm when not under load. Calculate the rotational speed of the saw blade when the motor is switched on. … … … … [3] (iv) Explain why the actual rotational speed in use may be less than the calculated speed. … … … [2] (v) Give one reason for having covers over the lubrication holes at each end of the motor. … … [1] (c) (i) State what is meant by a plain bearing. … … [1] (ii) Fig. 10.5 shows a tapered roller bearing with a section showing a wheel hub and axle that uses tapered roller bearings. tapered rollers inner race outer race wheel hub outer race axle tapered rollers adjustment nut inner race Fig. 10.5 Explain why tapered roller bearings are used in pairs with the tapered ends of the rollers facing each other on the axle. … … … … [3]

25 marks

Mark scheme: 10(a)(i) X is a ratchet [1] 2 Do not allow reverse answers. Y is a pawl [1] 10(a)(ii) Description to include: shaft can only rotate in one direction, ratchet rotates 3 1 mark for each valid point up to maximum with the shaft, pawl is free to oscillate, engages with ratchet using gravity to 3. drop, shaft is prevented from turning backwards by pawl. Allow 2 marks for a single point fully justified. 10(a)(iii) Benefits of tapered shaft include: can always fit tightly onto shaft, no method of 1 Allow other valid reasons locking in place is required, can be easily removed from the shaft, square on shaft gives is a positive method that does not allow any slipping 10(a)(iv) Mechanical advantage is a measure of advantage gained [1] 2 Award marks for understanding shown. by using a mechanism to transmit force [1] 10(a)(v) Sketch or notes showing an increase in distance between centre of shaft and 3 centre of handle [1] Notes showing understanding of how advantage is increased [1] Method of reducing friction between the hand grip and hand of the user [1] 10(b)(i) Reasons could include: four holes provide a stable method of mounting, the 2 Allow other valid reasons load is spread over a greater surface area than if using only two holes, slots allow for positioning and tensioning of the motor [2  1] 10(b)(ii) Methods used could include: a lever to force the motor back, tensioning the 2 1 mark for each valid point included in belt, bolts tightened gradually while motor is held in position, check made on sketches or notes. tension of belt before fully tightening the bolts, a spring operated idler pulley Valid principle used [1] clear notes / sketches [1] 10(b)(iii) Motor pulley / saw blade pulley = 64 / 46 = 1.391 [1] 3 Correct answer with no working = 3 marks 1.391  motor speed 2850 rpm [1] Allow rounding differences. = 3965 rpm [1] 10(b)(iv) Explanation to include: frictional losses, heat and sound produced when 2 1 mark for each valid point, maximum 2. cutting, size and weight of blade, pressure of wood on blade, Allow 2 marks for a single point fully poor / inadequate lubrication, slipping belt on pulley [2 1] explained. 10(b)(v) The covers will prevent dust, sawdust etc from entering the lubrication hole 1 and being drawn into the bearings 10(c)(i) A plain bearing is a simple bearing with no moving parts. 1 It will normally be made of a material that has friction reducing properties. Material will be softer than the shaft that is running in it. 10(c)(ii) Using tapered roller bearings in pairs allows: adjustment of the bearings, both 3 AOVR radial and axial/thrust loading can be controlled, heavy loads to be supported, 1 mark for each point included up to three. support over an increased axle distance, easy lubrication with grease Allow 2 marks for a single point described in depth.

This question in 0445/43 Oct/Nov 2024

5 Explain why spur gears are used to transmit motion in a mechanism. … … … [2]

2 marks

Mark scheme: 5 Explanation for using spur gears will include: 2 Accept any other valid response • Where slippage is undesirable Allow reference to fitting into a small space. • Where changing a gear ratio / speed is required • To change direction of rotation • To multiply torque • To position parts of a system precisely. [2  1]

This question in 0445/41 May/June 2025

6 Describe how two shafts can be made to rotate in the same direction using spur gears. … … … [2]

2 marks

Mark scheme: 6 A change of direction when using spur gears is achieved by 2 Allow mark for understanding shown. using an idler gear, [1] shafts on gear systems with an odd number of elements will rotate in the same direction. [1]

This question in 0445/41 May/June 2025

7 Use sketches and notes to show a parallel linkage. [2]

2 marks

Mark scheme: 7 2 Shape of linkage [1], positions of either fixed or moving pivots marked. [1]

This question in 0445/41 May/June 2025

10 Fig. 10.1 shows a concrete canopy over the front of a warehouse building. The canopy is supported either side by steel structures that resist forces caused by the weight of the concrete canopy. A detailed view of one of the steel structures is shown. link threaded sleeve steel rods concrete canopy steel X poles concrete pile 1.5 m deep Fig. 10.1 (a) (i) Name the force acting on each of the steel rods. … [1] (ii) Explain how the threaded sleeve can be used to provide adjustment on the steel rods. … … … … [3] (iii) Part X in Fig. 10.1 is one of four features at the point where the steel poles are joined. Name part X and explain the part that it plays in supporting the concrete canopy. … … … … [3] (iv) State the purpose of the links at each end of the steel rods. … … [1] (v) A concrete pile 1.5 m deep is used as the foundation for the steel structure. Give two reasons why concrete is used as the foundation. 1 … 2 … [2] (b) Fig. 10.2 shows the same wheelbarrow loaded with bricks in two different ways. X A B Fig. 10.2 (i) State the order of lever that is used in a wheelbarrow. … [1] (ii) Name the type of structural member at X. … [1] (iii) Explain the change in efficiency caused by the different methods of loading the wheelbarrow. … … … … [3] (iv) Describe how equilibrium is maintained when a wheelbarrow is in use. … … … [2] (v) Fig. 10.3 shows wheelbarrow A loaded with 38 bricks, each brick weighing 2.1 kg. Calculate the effort required to lift the loaded wheelbarrow. 1 kg = 9.81 N 38 bricks 980 240 Fig. 10.3 … … … … [3] (c) Fig. 10.4 shows a roof truss made of softwood. enlarged view of nail plate Fig. 10.4 (i) The softwood is joined using nail plates. Give two advantages of using nail plates rather than traditional joints. 1 … … 2 … … [2] (ii) Describe the defects that a manufacturer would look for when selecting lengths of softwood for use in the roof truss. … … … … [3]

25 marks

Mark scheme: 10(a)(i) Each of the steel rods is in tension. 1 10(a)(ii) The sleeve can be used to reduce or increase the effective 3 Award marks for understanding shown. length of the rods, [1] using a right-hand thread in one and a Allow 2 marks for a single point fully explained. left-hand thread in the other [1]. Turning the sleeve will act on both rods at the same time. [1] 10(a)(iii) Part X is a gusset plate, [1]. The plates reduce / prevent 3 Allow reference to the gusset plate supporting the joint or movement [1], which could distort the two poles. [1] distributing the load. 10(a)(iv) The links will allow some movement in the rods. 1 10(a)(v) • Concrete is strong in compression 2 No mark for ‘strong material’ with no indication that it is • It can be poured on site ‘strong in compression’. • Concrete provides a solid foundation with no movement • The concrete pile will be below the frost line so has little chance of moving or being damaged by frost • Will resist water damage. • Durable / no maintenance required [2  1] 10(b)(i) The wheelbarrow is a second order / class 2 lever. 1 10(b)(ii) The structural member at X is a strut. 1 Allow ‘brace’. 10(b)(iii) The explanation should include: 3 1 mark for each valid point made. Award 2 marks for a • In wheelbarrow A the load is closer to the fulcrum single point fully explained. • The lever will give increased mechanical advantage • This will increase the efficiency • Wheelbarrow B is less efficient. 10(b)(iv) • When the wheelbarrow is stationary, resting on the 2 Accept any other valid response ground it will be in equilibrium, it is effectively a tripod Any two valid points mentioned in the description. • When the handles of the wheelbarrow are lifted the Allow 2 marks for a single point fully described. device will be unstable • The user’s hands pulling / pushing on either handle maintain equilibrium in a moving wheelbarrow. 10(b)(v) The load is 38  2.1  9.81 = 782.8 N [1] 3 Award full marks for correct answer with no working. 240  782.8 = 1220  Effort [1] Effort = 240  782.8 / 1220 = 153.9 N [1] 10(c)(i) Advantages of nail plates will include: 2 Allow any other valid alternatives Allows offsite construction • Low cost • Secure method • Can be applied using a press • Less skill required • Increased speed of production. [2  1] 10(c)(ii) Defects that can be avoided during selection include: 3 Award marks for understanding shown. • Bent / warped pieces 1 mark for each valid point in description. • Large knots Allow 2 marks for a single point fully described • Splits / shakes Allow mark for checking moisture level. • Signs of insect damage • Signs of rot.

This question in 0445/41 May/June 2025

11 Fig. 11.1 shows two views of a badge-making machine which is used to press a clear plastic sheet over a paper badge and badge blank. spring lever paper badge placed on top of blank view A pressure pad view B Fig. 11.1 (a) (i) State the order of lever used in the badge-making machine. … [1] (ii) Indicate the positions of the load, effort and fulcrum on view B. [3] (iii) Describe the conversion of motion that will take place when the lever is operated. … to … motion [2] (iv) State the purpose of the spring labelled in view A. … [1] (b) Fig. 11.2 shows a block and tackle mechanism. effort load Fig. 11.2 (i) Calculate the effort needed to raise a load of 1250 N if the efficiency of the block and tackle is 88%. … … … … [4] (ii) Explain the factors that could cause the block and tackle system to lose efficiency. … … … [2] (iii) Give two ways that the efficiency could be increased. 1 … … 2 … … [2] (c) Fig. 11.3 shows a gravity fed oiler used to lubricate a shaft on an industrial machine. oiler flat belt bearing shaft Fig. 11.3 (i) Describe the maintenance that needs to be carried out on the gravity fed oiler. … … … [2] (ii) State the most likely type of bearing that will be fitted to allow the shaft to rotate. … [1] (iii) Give one alternative type of bearing that will reduce the maintenance required. … [1] (iv) Give two drawbacks of using a flat belt to transmit motion. 1 … … 2 … … [2] (v) Add sketches and notes to Fig. 11.4 to show one method of keeping a flat belt in tension. Fig. 11.4 [4]

25 marks

Mark scheme: 11(a)(i) Second order or second class lever. 1 11(a)(ii) 3 No mark for two labels showing the same letter in different positions. 1 mark for each correctly labelled. 11(a)(iii) Oscillating motion [1] 2 is converted to reciprocating motion [1]. 11(a)(iv) The spring will return the pressure pad when the lever is 1 raised. 11(b)(i) VR = 5 [1] 4 Award full marks for correct answer with no working. MA = 5  0.88 = 4.4 [1] Effort = 1250 / 4.4 [1] = 284.1 N [1] 11(b)(ii) Loss of efficiency will be due to: 2 Accept any other valid response • Friction in pulley bearings 1 mark for each point included in the explanation. • Quality of the bearings Allow 2 marks for a single point fully explained. • Increased number of pulleys in the system 1 mark only for reference to a lack of lubrication. • Loss of energy due to heat and sound generated. [2  1] 11(b)(iii) Efficiency can be increased by: 2 • Lubricating the bearings on each pulley • Use of ball bearings or needle bearings on pulleys • Increase the diameter of the pulley. [2  1] 11(c)(i) The maintenance process for the gravity fed oiler will 2 Allow other valid points. include: • Keeping the exterior clean to keep dirt out of the bearings. • Regular checks on the oil level. • Checks and adjustment of the oil flow • Check that oil is going to the bearings. [2  1] 11(c)(ii) The bearing is likely to be a plain bearing. 1 11(c)(iii) A sealed ball bearing or needle bearing will remove / re the 1 Bearing must be described as ‘sealed’ for mark. need for lubrication and will prevent oil from getting onto the machine’s exterior surface. 11(c)(iv) Drawbacks will include: 2 Allow other valid disadvantages. • Belt can come off the pulleys more easily • More prone to slipping on the belt • Generally narrower section so will stretch more easily • Could be noisier than a vee belt or chain drive. [2  1] 11(c)(v) Clear sketches [2] 4 Workable solution [1] Supporting notes [1] The method could be: • A spring tensioned roller pressing against the belt • One of the pulleys being movable, mounted on a slot • One pulley mounted on a quadrant which can be swung down to provide tension.

This question in 0445/41 May/June 2025

4 Friction can be reduced by design. Give two examples of how friction can be reduced when designing a car. 1 … … 2 … … [2]

2 marks

Mark scheme: 4 Friction can be reduced by: 2 Accept any other valid response • use of a streamlined / aerodynamic shape • making mating surfaces smoother Description should relate to car design, do not allow • reducing contact between surfaces reference to oil or grease. • use of efficient bearings • use of materials with a low coefficient of friction • reduced weight / parts count • accuracy in manufacture [2  1]

This question in 0445/42 May/June 2025

5 Fig. 5.1 shows part of the drive mechanism on a steam locomotive. drive mechanism Fig. 5.1 Describe how friction could be reduced in the moving parts of the drive mechanism. … … … [2]

2 marks

Mark scheme: 5 Use of lubrication [1] 2 1 mark for each valid point in the description. Allow 2 marks With oil or grease [1] for a single point fully explained Reference to increased efficiency [1] [2  1]

This question in 0445/42 May/June 2025

6 (a) State the type of motion associated with each symbol in Fig. 6.1. A B C D A … B … C … D … Fig. 6.1 [4] (b) Give one example of a mechanism that uses motion B. … [1]

5 marks

Mark scheme: 6(a) A – reciprocating motion 4 B – oscillating motion C – rotary motion (accept circular) D – linear motion. [4  1] 6(b) Mechanisms could include: 1 Accept any other valid response • Clock pendulum Allow: • Swing Specific type of pendulum clock • Tuning fork Crank and slider • Bird’s wings Bell crank

This question in 0445/42 May/June 2025

10 (a) Fig. 10.1 shows a pair of garden loppers used to cut branches from trees. 50 475 Fig. 10.1 (i) State the order of lever used in the garden loppers. … [1] (ii) Add labels to Fig. 10.1 to indicate the position of the fulcrum, load and effort. [3] (iii) Describe how the garden loppers can be maintained to prevent loss of efficiency. … … … … [2] (iv) Calculate the mechanical advantage in the garden loppers. … … … … [2] (b) Fig. 10.2 shows part of a rack and pinion gear system for raising and lowering a drill table. drill table crank handle rack drill pillar worm gear plain bearing crank handle rack 30 t pinion casing Fig. 10.2 (i) The pitch of the teeth on the rack is 2.5 mm. Calculate the distance and direction of movement of the drill table when the crank handle is turned clockwise through 720 degrees. … … … … [3] (ii) Explain why the rack and pinion system has been chosen for moving the drill table. … … … [2] (iii) The worm gear in Fig. 10.2 rotates in a plain bearing. Describe what is meant by a plain bearing. … … [2] (iv) Give two reasons for choosing the plain bearing shown in Fig. 10.2. 1 … 2 … [2] (v) State two actions that should be taken to prevent wear in the drill rack and pinion gear system. 1 … 2 … [2] (c) (i) Explain what is meant by an idler gear in a gear mechanism. … … … [3] (ii) Fig. 10.3 shows a simple gear mechanism. Driver gear A rotates clockwise at 150 rpm. Calculate the speed of gear B and indicate the direction of rotation. gear B 15 t gear A 25 t Fig. 10.3 … … … [3]

25 marks

Mark scheme: 10(a)(i) It is a first order or first class lever 1 10(a)(ii) 3 Do not allow mark for an identification that appears more than once. 1 mark for each correct label 10(a)(iii) Maintenance will include: 2 1 mark for each valid point in the description. Allow 2 marks • Lubrication of the blades for a single point fully described. • Sharpening the blades • Adjustment of centre nut • Cleaning the blades 10(a)(iv) Mechanical advantage = 475 / 50 [1] = 9.5 [1] 2 10(b)(i) 720 º = 2 rotations, [1] 3 For two turns of the crank handle to drill table will move (2.5  2) mm. = 5 mm [1] The direction of movement is upwards [1] 10(b)(ii) Reasons for choice of rack and pinion will include: 2 1 mark for each valid point in the explanation. Allow 2 marks • The table is heavy and with the gear system it cannot for a single point fully explained. slip / fall. • Precise movement is possible / good control over the height • Rack can run the full length of the pillar • High mechanical advantage • Rack can resist full weight of the table. 10(b)(iii) Description may include: 2 1 mark for each valid point in the description. Allow 2 marks • A plain bearing can allow sliding or rotation of the shaft for a single point fully justified. within it. • Can be made from a range of materials • Only has one component in it • There are no moving parts • Will not prevent thrust 10(b)(iv) • Generally low cost 2 Accept any other valid response • Replaceable when worn • Low maintenance 10(b)(v) • The rack should be kept clean and free from swarf. 2 • Lubrication • Using grease rather than oil [2  1] 10(c)(i) Explanation could include: 3 1 mark for each valid point in the explanation. Allow 2 an idler gear: marks for a single point fully explained. • Will transfer motion / torque from one gear to another after being placed • Is placed between the input and output shafts [1] • Will cause two shafts to rotate in the same direction when placed between them [1] • Will not alter the relative speed of the shafts that it connects. [1] • Can vary distance between input and output shafts [1] 10(c)(ii) Ratio of driver: driven= 25:15 = 1.6667 [1] 3 Award full marks if correct answer is given with no working. Driver speed = 150 rpm Driven speed = 1.6667  150 = 250 rpm [1] Gear B will rotate anticlockwise [1]

This question in 0445/42 May/June 2025

5 Explain why spur gears are used to transmit motion in a mechanism. … … … [2]

2 marks

Mark scheme: 5 Explanation for using spur gears will include: 2 Accept any other valid response • Where slippage is undesirable Allow reference to fitting into a small space. • Where changing a gear ratio / speed is required • To change direction of rotation • To multiply torque • To position parts of a system precisely. [2  1]

This question in 0445/43 May/June 2025

6 Describe how two shafts can be made to rotate in the same direction using spur gears. … … … [2]

2 marks

Mark scheme: 6 A change of direction when using spur gears is achieved by 2 Allow mark for understanding shown. using an idler gear, [1] shafts on gear systems with an odd number of elements will rotate in the same direction. [1]

This question in 0445/43 May/June 2025

7 Use sketches and notes to show a parallel linkage. [2]

2 marks

Mark scheme: 7 2 Shape of linkage [1], positions of either fixed or moving pivots marked. [1]

This question in 0445/43 May/June 2025

10 Fig. 10.1 shows a concrete canopy over the front of a warehouse building. The canopy is supported either side by steel structures that resist forces caused by the weight of the concrete canopy. A detailed view of one of the steel structures is shown. link threaded sleeve steel rods concrete canopy steel X poles concrete pile 1.5 m deep Fig. 10.1 (a) (i) Name the force acting on each of the steel rods. … [1] (ii) Explain how the threaded sleeve can be used to provide adjustment on the steel rods. … … … … [3] (iii) Part X in Fig. 10.1 is one of four features at the point where the steel poles are joined. Name part X and explain the part that it plays in supporting the concrete canopy. … … … … [3] (iv) State the purpose of the links at each end of the steel rods. … … [1] (v) A concrete pile 1.5 m deep is used as the foundation for the steel structure. Give two reasons why concrete is used as the foundation. 1 … 2 … [2] (b) Fig. 10.2 shows the same wheelbarrow loaded with bricks in two different ways. X A B Fig. 10.2 (i) State the order of lever that is used in a wheelbarrow. … [1] (ii) Name the type of structural member at X. … [1] (iii) Explain the change in efficiency caused by the different methods of loading the wheelbarrow. … … … … [3] (iv) Describe how equilibrium is maintained when a wheelbarrow is in use. … … … [2] (v) Fig. 10.3 shows wheelbarrow A loaded with 38 bricks, each brick weighing 2.1 kg. Calculate the effort required to lift the loaded wheelbarrow. 1 kg = 9.81 N 38 bricks 980 240 Fig. 10.3 … … … … [3] (c) Fig. 10.4 shows a roof truss made of softwood. enlarged view of nail plate Fig. 10.4 (i) The softwood is joined using nail plates. Give two advantages of using nail plates rather than traditional joints. 1 … … 2 … … [2] (ii) Describe the defects that a manufacturer would look for when selecting lengths of softwood for use in the roof truss. … … … … [3]

25 marks

Mark scheme: 10(a)(i) Each of the steel rods is in tension. 1 10(a)(ii) The sleeve can be used to reduce or increase the effective 3 Award marks for understanding shown. length of the rods, [1] using a right-hand thread in one and a Allow 2 marks for a single point fully explained. left-hand thread in the other [1]. Turning the sleeve will act on both rods at the same time. [1] 10(a)(iii) Part X is a gusset plate, [1]. The plates reduce / prevent 3 Allow reference to the gusset plate supporting the joint or movement [1], which could distort the two poles. [1] distributing the load. 10(a)(iv) The links will allow some movement in the rods. 1 10(a)(v) • Concrete is strong in compression 2 No mark for ‘strong material’ with no indication that it is • It can be poured on site ‘strong in compression’. • Concrete provides a solid foundation with no movement • The concrete pile will be below the frost line so has little chance of moving or being damaged by frost • Will resist water damage. • Durable / no maintenance required [2  1] 10(b)(i) The wheelbarrow is a second order / class 2 lever. 1 10(b)(ii) The structural member at X is a strut. 1 Allow ‘brace’. 10(b)(iii) The explanation should include: 3 1 mark for each valid point made. Award 2 marks for a • In wheelbarrow A the load is closer to the fulcrum single point fully explained. • The lever will give increased mechanical advantage • This will increase the efficiency • Wheelbarrow B is less efficient. 10(b)(iv) • When the wheelbarrow is stationary, resting on the 2 Accept any other valid response ground it will be in equilibrium, it is effectively a tripod Any two valid points mentioned in the description. • When the handles of the wheelbarrow are lifted the Allow 2 marks for a single point fully described. device will be unstable • The user’s hands pulling / pushing on either handle maintain equilibrium in a moving wheelbarrow. 10(b)(v) The load is 38  2.1  9.81 = 782.8 N [1] 3 Award full marks for correct answer with no working. 240  782.8 = 1220  Effort [1] Effort = 240  782.8 / 1220 = 153.9 N [1] 10(c)(i) Advantages of nail plates will include: 2 Allow any other valid alternatives Allows offsite construction • Low cost • Secure method • Can be applied using a press • Less skill required • Increased speed of production. [2  1] 10(c)(ii) Defects that can be avoided during selection include: 3 Award marks for understanding shown. • Bent / warped pieces 1 mark for each valid point in description. • Large knots Allow 2 marks for a single point fully described • Splits / shakes Allow mark for checking moisture level. • Signs of insect damage • Signs of rot.

This question in 0445/43 May/June 2025

11 Fig. 11.1 shows two views of a badge-making machine which is used to press a clear plastic sheet over a paper badge and badge blank. spring lever paper badge placed on top of blank view A pressure pad view B Fig. 11.1 (a) (i) State the order of lever used in the badge-making machine. … [1] (ii) Indicate the positions of the load, effort and fulcrum on view B. [3] (iii) Describe the conversion of motion that will take place when the lever is operated. … to … motion [2] (iv) State the purpose of the spring labelled in view A. … [1] (b) Fig. 11.2 shows a block and tackle mechanism. effort load Fig. 11.2 (i) Calculate the effort needed to raise a load of 1250 N if the efficiency of the block and tackle is 88%. … … … … [4] (ii) Explain the factors that could cause the block and tackle system to lose efficiency. … … … [2] (iii) Give two ways that the efficiency could be increased. 1 … … 2 … … [2] (c) Fig. 11.3 shows a gravity fed oiler used to lubricate a shaft on an industrial machine. oiler flat belt bearing shaft Fig. 11.3 (i) Describe the maintenance that needs to be carried out on the gravity fed oiler. … … … [2] (ii) State the most likely type of bearing that will be fitted to allow the shaft to rotate. … [1] (iii) Give one alternative type of bearing that will reduce the maintenance required. … [1] (iv) Give two drawbacks of using a flat belt to transmit motion. 1 … … 2 … … [2] (v) Add sketches and notes to Fig. 11.4 to show one method of keeping a flat belt in tension. Fig. 11.4 [4]

25 marks

Mark scheme: 11(a)(i) Second order or second class lever. 1 11(a)(ii) 3 No mark for two labels showing the same letter in different positions. 1 mark for each correctly labelled. 11(a)(iii) Oscillating motion [1] 2 is converted to reciprocating motion [1]. 11(a)(iv) The spring will return the pressure pad when the lever is 1 raised. 11(b)(i) VR = 5 [1] 4 Award full marks for correct answer with no working. MA = 5  0.88 = 4.4 [1] Effort = 1250 / 4.4 [1] = 284.1 N [1] 11(b)(ii) Loss of efficiency will be due to: 2 Accept any other valid response • Friction in pulley bearings 1 mark for each point included in the explanation. • Quality of the bearings Allow 2 marks for a single point fully explained. • Increased number of pulleys in the system 1 mark only for reference to a lack of lubrication. • Loss of energy due to heat and sound generated. [2  1] 11(b)(iii) Efficiency can be increased by: 2 • Lubricating the bearings on each pulley • Use of ball bearings or needle bearings on pulleys • Increase the diameter of the pulley. [2  1] 11(c)(i) The maintenance process for the gravity fed oiler will 2 Allow other valid points. include: • Keeping the exterior clean to keep dirt out of the bearings. • Regular checks on the oil level. • Checks and adjustment of the oil flow • Check that oil is going to the bearings. [2  1] 11(c)(ii) The bearing is likely to be a plain bearing. 1 11(c)(iii) A sealed ball bearing or needle bearing will remove / re the 1 Bearing must be described as ‘sealed’ for mark. need for lubrication and will prevent oil from getting onto the machine’s exterior surface. 11(c)(iv) Drawbacks will include: 2 Allow other valid disadvantages. • Belt can come off the pulleys more easily • More prone to slipping on the belt • Generally narrower section so will stretch more easily • Could be noisier than a vee belt or chain drive. [2  1] 11(c)(v) Clear sketches [2] 4 Workable solution [1] Supporting notes [1] The method could be: • A spring tensioned roller pressing against the belt • One of the pulleys being movable, mounted on a slot • One pulley mounted on a quadrant which can be swung down to provide tension.

This question in 0445/43 May/June 2025

4 Fig. 4.1 shows three spur gears used to connect the drive shafts on gears A and C. A C B Fig. 4.1 (a) Add arrows to Fig. 4.1 to show the direction of rotation of gears B and C. [2] (b) Explain why gears A and C are fixed to their shafts but gear B is free to rotate. … … … [2]

4 marks

Mark scheme: 4(a) 2 1 mark for each arrow correctly drawn. 4(b) Gears A and C need to rotate with their shafts. 2 1 mark for each point made in explanation. Gear B is an idler so can rotate on the shaft

This question in 0445/41 Oct/Nov 2025

5 Give two reasons for using lubrication in a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 5 Lubrication can be used to: 2 AOVR • Reduce the effects of friction 1 mark for each point made. • Reduce wear in the mechanism • Cool a mechanism • Reduce noise produced by the mechanism. [2  1]

This question in 0445/41 Oct/Nov 2025

6 Draw the symbols used to indicate reciprocating motion and oscillating motion. reciprocating motion oscillating motion [2]

2 marks

Mark scheme: 6 2 [2  1]

This question in 0445/41 Oct/Nov 2025

10 Fig. 10.1 shows a peg puller for removing large tent pegs from the ground. gripping jaws side supports A baseplate 200 × 120 steel lever arm tent peg Fig. 10.1 (a) (i) State the order of lever used in the peg puller. … [1] (ii) Give the name of feature A on the baseplate in Fig. 10.1. … [1] (iii) State the purpose of feature A. … [1] (iv) Explain why the base plate is needed at the point of contact with the ground. … … … [2] (v) Name the force that will act on the ground beneath the base plate. … [1] (vi) Fig. 10.2 shows a dimensioned view of the peg puller. steel lever arm X Y steel side plates 1500 steel lever arm 130 Fig. 10.2 Name the forces that will act on the upper surface X and the lower surface Y of the steel lever arm when it is operated. X … Y … [2] (vii) State one method that could be used to permanently join the steel side plates to the steel lever arm. … [1] (viii) Calculate the approximate force that is available to pull the tent peg when an effort of 200 N is applied to the end of the lever arm. Include units in your answer. … … … … [3] (b) (i) Using sketches and notes, complete Fig. 10.3 to show a beam supported by walls A and B. A B Fig. 10.3 [2] (ii) Using sketches and notes, complete Fig. 10.4 to show a tie at joint C. C Fig. 10.4 [2] (iii) Using sketches and notes, complete Fig. 10.5 to show a strut at joint D. D Fig. 10.5 [2] (c) Fig. 10.6 shows the layout of timber in the base of a small wooden building. spacing pieces Fig. 10.6 (i) Give two features of the timber used in the layout that will affect performance of the structure. 1 … 2 … [2] (ii) Give two reasons for using the spacing pieces in Fig. 10.6. 1 … 2 … [2] (iii) Use sketches and notes to show one way of securing the spacing pieces in position. List any fixings that will be used. [3]

25 marks

Mark scheme: 10(a)(i) First order lever 1 10(a)(ii) Feature A is a gusset plate 1 10(a)(iii) Feature A is used to support the joints between the 1 Award marks for understanding shown. baseplate and side supports. 10(a)(iv) If the ground is soft and if there were no baseplate the 2 Allow any other valid points. device would sink into the ground [1] Explanation to include any two valid points, 2 marks. The baseplate provides a larger surface area which is less Award 2 marks for a full explanation of a single point. likely to sink when pressure is applied to the lever arm [1] Efficiency of the peg puller is improved [1] The baseplate acts as a fulcrum [1] 10(a)(v) The force acting on the ground is compression. 1 10(a)(vi) The force acting on surface X is tension [1] 2 The force acting on surface Y is compression [1] 10(a)(vii) Welding is used to join the steel side plates to the steel 1 Allow brazing. Do not allow riveting. lever arm. 10(a)(viii) force  130 = 200  1500 [1] 3 Award 3 marks for correct answer with no working. force = 300000 / 130 [1] force = 2307.7 N [1] 10(b)(i) Accurately sketch / notes [1] 2 Proportions suitable [1] 10(b)(ii) Accurately sketch / notes / drawn in correct position [1] 2 If both strut and tie are shown 1 mark only Proportions suitable [1] 10(b)(iii) Accurately sketch / notes / drawn in correct position [1] 2 No mark for strut drawn with a single line. Proportions suitable [1] If both strut and tie are shown 1 mark only 10(c)(i) Features affecting performance will include: 2 Accept valid alternatives. • Knots • Shakes • Splits • Twisting • Finish or treatment needed on the timber [2  1] 10(c)(ii) The spacing pieces will: 2 • Help to prevent twisting / warping of the joists [1] • Provide extra support to floor [1] • Maintain spacing between joists. [1] [2  1] 10(c)(iii) The spacing pieces are staggered across the width to allow 3 Example method screws / nails to be fitted. • Functional method [1] • Clear sketch / notes showing method [1] • List of fixings screws / nails / joist hangers [1] • Mechanical joint used / mortise and tenon / bridle joint.[1]

This question in 0445/41 Oct/Nov 2025

11 Fig. 11.1 shows an air compressor driven by an electric motor. electric motor air compressor vee belt Fig. 11.1 (a) The electric motor uses a vee belt to connect to the air compressor. (i) Name two other types of belt that could be used. 1 … 2 … [2] (ii) Explain why the vee belt is the most suitable method of connecting the electric motor to the air compressor. … … … [2] (b) Fig. 11.2 shows the main moving parts of the air compressor. expanding rings used to form a tight seal B 50 diameter 12.5 12.5 B Fig. 11.2 (i) Use words from the list below to complete the description of the air compressor operating. Not all of the words will be used. bearing connecting crankshaft cylinder gear piston pulley The vee … transfers motion to the … causing it to rotate. This in turn causes the … rod to move the … . [4] (ii) Name the type of mechanism used to convert motion in the air compressor. … [2] (iii) Calculate the volume of air that is displaced for each rotation of part B. The formula for the area of a circle is A = π r2. … … … … mm3 [3] (c) (i) Fig. 11.3 shows the small oil holes used to lubricate the plain bearings. oil holes plain bearings Fig. 11.3 Explain why grease would not be suitable for lubricating the plain bearings. … … … [2] (ii) Name two alternative types of bearing that could have been used. 1 … 2 … [2] (iii) Give one practical benefit of using plain bearings in the compressor. … … [1] (d) Fig. 11.4 shows two hexagonal head bolts of the same length, diameter and material. 1.5 0.75 A B Fig. 11.4 (i) Give one difference that will be noticed when fitting the bolts into a threaded hole. … [1] (ii) Explain why bolt B, which has a smaller thread pitch, will resist higher torque when being tightened. … … … [2] (e) Fig. 11.5 shows a gear system. motor speed = 850 rpm motor 30t 40t 15t Fig. 11.5 (i) State the velocity ratio of the worm gear and 30t gear. … [1] (ii) Calculate the speed of the 40t gear when the motor is turning. … … … … [3]

25 marks

Mark scheme: 11(a)(i) Other types of belt could be flat, toothed or round. 2 Accept ‘plain belt’. Sketches must be identified with a name for mark to be [2  1] awarded. 11(a)(ii) Reasons for the vee belt being most suitable are: 2 Allow any other valid points. • Transmit power very well Explanation to include any two valid points, 2 marks. • Limited slip between belt and pulleys / high friction force Award 2 marks for a full explanation of a single point. • Low noise and vibration levels • Easy to install and maintain. 11(b)(i) The vee pulley transfers motion to the crankshaft causing it 4 1 mark for each word correctly used to rotate. This in turn causes the connecting rod to move the piston . [4  1] 11(b)(ii) Crank [1] / slider [1] mechanism. 2 11(b)(iii) Area of piston = Π r2 = 3.142  252 = 1963.75 (1963.495 on 3 Award 3 marks for correct answer with no working. calculator) [1] Throw of piston = 12.5  2 = 25 [1] Volume displaced = 1963.75  25 = 49093.75 mm3 or 49 087.39 [1] 11(c)(i)) Grease would not be suitable because: 2 Allow any other valid points. • It is too thick / viscous to flow through the oil holes. Explanation to include any two valid points, 2 marks. • The bearing also uses oil to carry away any particles Award 2 marks for a full explanation of a single point. from the bearing. • Grease would keep the particles in the bearing, allowing metal to metal contact. 11(c)(ii) Roller or ball bearings could have been used. 2 Accept needle bearings [2  1] 11(c)(iii) Benefits of plain bearings include: 1 Allow any other valid points. • Smaller diameter • Low maintenance • Plain bearings support higher loads. 11(d)(i) Differences in use include: 1 AOVR • More difficult to start bolt B in threaded hole / nut • Easier to start bolt A in threaded hole • Easy to cross thread bolt B when inserting • More turns needed to move bolt B through a set linear distance • Faster to insert bolt A. 11(d)(ii) • The core diameter of bolt B is larger than for bolt A due 2 Allow any other valid points. to smaller pitch and lower depth of thread Explanation to include any two valid points, 2 marks. • Larger diameter will have greater resistance to shear Award 2 marks for a full explanation of a single point. forces • Higher torque can be applied before the bolt will fail / shear. • More precise in transmitting motion 11(e)(i) The velocity ratio of the worm gear is 30:1 1 11(e)(ii) Worm gear ratio 30:1 15 t:40 t ratio 2.666:1 [1] 3 Allow ecf from (d)(ii). Total reduction ratio = 30  2.666 = 80:1 [1] Speed of 40 t gear = 850 / 80 = 10.625 rpm [1] Award 3 marks for correct answer with no working.

This question in 0445/41 Oct/Nov 2025

4 Fig. 4.1 shows three spur gears used to connect the drive shafts on gears A and C. A C B Fig. 4.1 (a) Add arrows to Fig. 4.1 to show the direction of rotation of gears B and C. [2] (b) Explain why gears A and C are fixed to their shafts but gear B is free to rotate. … … … [2]

4 marks

Mark scheme: 4(a) 2 1 mark for each arrow correctly drawn. 4(b) Gears A and C need to rotate with their shafts. 2 1 mark for each point made in explanation. Gear B is an idler so can rotate on the shaft

This question in 0445/42 Oct/Nov 2025

5 Give two reasons for using lubrication in a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 5 Lubrication can be used to: 2 AOVR • Reduce the effects of friction 1 mark for each point made. • Reduce wear in the mechanism • Cool a mechanism • Reduce noise produced by the mechanism. [2  1]

This question in 0445/42 Oct/Nov 2025

6 Draw the symbols used to indicate reciprocating motion and oscillating motion. reciprocating motion oscillating motion [2]

2 marks

Mark scheme: 6 2 [2  1]

This question in 0445/42 Oct/Nov 2025

10 Fig. 10.1 shows a peg puller for removing large tent pegs from the ground. gripping jaws side supports A baseplate 200 × 120 steel lever arm tent peg Fig. 10.1 (a) (i) State the order of lever used in the peg puller. … [1] (ii) Give the name of feature A on the baseplate in Fig. 10.1. … [1] (iii) State the purpose of feature A. … [1] (iv) Explain why the base plate is needed at the point of contact with the ground. … … … [2] (v) Name the force that will act on the ground beneath the base plate. … [1] (vi) Fig. 10.2 shows a dimensioned view of the peg puller. steel lever arm X Y steel side plates 1500 steel lever arm 130 Fig. 10.2 Name the forces that will act on the upper surface X and the lower surface Y of the steel lever arm when it is operated. X … Y … [2] (vii) State one method that could be used to permanently join the steel side plates to the steel lever arm. … [1] (viii) Calculate the approximate force that is available to pull the tent peg when an effort of 200 N is applied to the end of the lever arm. Include units in your answer. … … … … [3] (b) (i) Using sketches and notes, complete Fig. 10.3 to show a beam supported by walls A and B. A B Fig. 10.3 [2] (ii) Using sketches and notes, complete Fig. 10.4 to show a tie at joint C. C Fig. 10.4 [2] (iii) Using sketches and notes, complete Fig. 10.5 to show a strut at joint D. D Fig. 10.5 [2] (c) Fig. 10.6 shows the layout of timber in the base of a small wooden building. spacing pieces Fig. 10.6 (i) Give two features of the timber used in the layout that will affect performance of the structure. 1 … 2 … [2] (ii) Give two reasons for using the spacing pieces in Fig. 10.6. 1 … 2 … [2] (iii) Use sketches and notes to show one way of securing the spacing pieces in position. List any fixings that will be used. [3]

25 marks

Mark scheme: 10(a)(i) First order lever 1 10(a)(ii) Feature A is a gusset plate 1 10(a)(iii) Feature A is used to support the joints between the 1 Award marks for understanding shown. baseplate and side supports. 10(a)(iv) If the ground is soft and if there were no baseplate the 2 Allow any other valid points. device would sink into the ground [1] Explanation to include any two valid points, 2 marks. The baseplate provides a larger surface area which is less Award 2 marks for a full explanation of a single point. likely to sink when pressure is applied to the lever arm [1] Efficiency of the peg puller is improved [1] The baseplate acts as a fulcrum [1] 10(a)(v) The force acting on the ground is compression. 1 10(a)(vi) The force acting on surface X is tension [1] 2 The force acting on surface Y is compression [1] 10(a)(vii) Welding is used to join the steel side plates to the steel 1 Allow brazing. Do not allow riveting. lever arm. 10(a)(viii) force  130 = 200  1500 [1] 3 Award 3 marks for correct answer with no working. force = 300000 / 130 [1] force = 2307.7 N [1] 10(b)(i) Accurately sketch / notes [1] 2 Proportions suitable [1] 10(b)(ii) Accurately sketch / notes / drawn in correct position [1] 2 If both strut and tie are shown 1 mark only Proportions suitable [1] 10(b)(iii) Accurately sketch / notes / drawn in correct position [1] 2 No mark for strut drawn with a single line. Proportions suitable [1] If both strut and tie are shown 1 mark only 10(c)(i) Features affecting performance will include: 2 Accept valid alternatives. • Knots • Shakes • Splits • Twisting • Finish or treatment needed on the timber [2  1] 10(c)(ii) The spacing pieces will: 2 • Help to prevent twisting / warping of the joists [1] • Provide extra support to floor [1] • Maintain spacing between joists. [1] [2  1] 10(c)(iii) The spacing pieces are staggered across the width to allow 3 Example method screws / nails to be fitted. • Functional method [1] • Clear sketch / notes showing method [1] • List of fixings screws / nails / joist hangers [1] • Mechanical joint used / mortise and tenon / bridle joint.[1]

This question in 0445/42 Oct/Nov 2025

11 Fig. 11.1 shows an air compressor driven by an electric motor. electric motor air compressor vee belt Fig. 11.1 (a) The electric motor uses a vee belt to connect to the air compressor. (i) Name two other types of belt that could be used. 1 … 2 … [2] (ii) Explain why the vee belt is the most suitable method of connecting the electric motor to the air compressor. … … … [2] (b) Fig. 11.2 shows the main moving parts of the air compressor. expanding rings used to form a tight seal B 50 diameter 12.5 12.5 B Fig. 11.2 (i) Use words from the list below to complete the description of the air compressor operating. Not all of the words will be used. bearing connecting crankshaft cylinder gear piston pulley The vee … transfers motion to the … causing it to rotate. This in turn causes the … rod to move the … . [4] (ii) Name the type of mechanism used to convert motion in the air compressor. … [2] (iii) Calculate the volume of air that is displaced for each rotation of part B. The formula for the area of a circle is A = π r2. … … … … mm3 [3] (c) (i) Fig. 11.3 shows the small oil holes used to lubricate the plain bearings. oil holes plain bearings Fig. 11.3 Explain why grease would not be suitable for lubricating the plain bearings. … … … [2] (ii) Name two alternative types of bearing that could have been used. 1 … 2 … [2] (iii) Give one practical benefit of using plain bearings in the compressor. … … [1] (d) Fig. 11.4 shows two hexagonal head bolts of the same length, diameter and material. 1.5 0.75 A B Fig. 11.4 (i) Give one difference that will be noticed when fitting the bolts into a threaded hole. … [1] (ii) Explain why bolt B, which has a smaller thread pitch, will resist higher torque when being tightened. … … … [2] (e) Fig. 11.5 shows a gear system. motor speed = 850 rpm motor 30t 40t 15t Fig. 11.5 (i) State the velocity ratio of the worm gear and 30t gear. … [1] (ii) Calculate the speed of the 40t gear when the motor is turning. … … … … [3]

25 marks

Mark scheme: 11(a)(i) Other types of belt could be flat, toothed or round. 2 Accept ‘plain belt’. Sketches must be identified with a name for mark to be [2  1] awarded. 11(a)(ii) Reasons for the vee belt being most suitable are: 2 Allow any other valid points. • Transmit power very well Explanation to include any two valid points, 2 marks. • Limited slip between belt and pulleys / high friction force Award 2 marks for a full explanation of a single point. • Low noise and vibration levels • Easy to install and maintain. 11(b)(i) The vee pulley transfers motion to the crankshaft causing it 4 1 mark for each word correctly used to rotate. This in turn causes the connecting rod to move the piston . [4  1] 11(b)(ii) Crank [1] / slider [1] mechanism. 2 11(b)(iii) Area of piston = Π r2 = 3.142  252 = 1963.75 (1963.495 on 3 Award 3 marks for correct answer with no working. calculator) [1] Throw of piston = 12.5  2 = 25 [1] Volume displaced = 1963.75  25 = 49093.75 mm3 or 49 087.39 [1] 11(c)(i)) Grease would not be suitable because: 2 Allow any other valid points. • It is too thick / viscous to flow through the oil holes. Explanation to include any two valid points, 2 marks. • The bearing also uses oil to carry away any particles Award 2 marks for a full explanation of a single point. from the bearing. • Grease would keep the particles in the bearing, allowing metal to metal contact. 11(c)(ii) Roller or ball bearings could have been used. 2 Accept needle bearings [2  1] 11(c)(iii) Benefits of plain bearings include: 1 Allow any other valid points. • Smaller diameter • Low maintenance • Plain bearings support higher loads. 11(d)(i) Differences in use include: 1 AOVR • More difficult to start bolt B in threaded hole / nut • Easier to start bolt A in threaded hole • Easy to cross thread bolt B when inserting • More turns needed to move bolt B through a set linear distance • Faster to insert bolt A. 11(d)(ii) • The core diameter of bolt B is larger than for bolt A due 2 Allow any other valid points. to smaller pitch and lower depth of thread Explanation to include any two valid points, 2 marks. • Larger diameter will have greater resistance to shear Award 2 marks for a full explanation of a single point. forces • Higher torque can be applied before the bolt will fail / shear. • More precise in transmitting motion 11(e)(i) The velocity ratio of the worm gear is 30:1 1 11(e)(ii) Worm gear ratio 30:1 15 t:40 t ratio 2.666:1 [1] 3 Allow ecf from (d)(ii). Total reduction ratio = 30  2.666 = 80:1 [1] Speed of 40 t gear = 850 / 80 = 10.625 rpm [1] Award 3 marks for correct answer with no working.

This question in 0445/42 Oct/Nov 2025

4 Fig. 4.1 shows three spur gears used to connect the drive shafts on gears A and C. A C B Fig. 4.1 (a) Add arrows to Fig. 4.1 to show the direction of rotation of gears B and C. [2] (b) Explain why gears A and C are fixed to their shafts but gear B is free to rotate. … … … [2]

4 marks

Mark scheme: 4(a) 2 1 mark for each arrow correctly drawn. 4(b) Gears A and C need to rotate with their shafts. 2 1 mark for each point made in explanation. Gear B is an idler so can rotate on the shaft

This question in 0445/43 Oct/Nov 2025

5 Give two reasons for using lubrication in a mechanism. 1 … 2 … [2]

2 marks

Mark scheme: 5 Lubrication can be used to: 2 AOVR • Reduce the effects of friction 1 mark for each point made. • Reduce wear in the mechanism • Cool a mechanism • Reduce noise produced by the mechanism. [2  1]

This question in 0445/43 Oct/Nov 2025

6 Draw the symbols used to indicate reciprocating motion and oscillating motion. reciprocating motion oscillating motion [2]

2 marks

Mark scheme: 6 2 [2  1]

This question in 0445/43 Oct/Nov 2025

10 Fig. 10.1 shows a peg puller for removing large tent pegs from the ground. gripping jaws side supports A baseplate 200 × 120 steel lever arm tent peg Fig. 10.1 (a) (i) State the order of lever used in the peg puller. … [1] (ii) Give the name of feature A on the baseplate in Fig. 10.1. … [1] (iii) State the purpose of feature A. … [1] (iv) Explain why the base plate is needed at the point of contact with the ground. … … … [2] (v) Name the force that will act on the ground beneath the base plate. … [1] (vi) Fig. 10.2 shows a dimensioned view of the peg puller. steel lever arm X Y steel side plates 1500 steel lever arm 130 Fig. 10.2 Name the forces that will act on the upper surface X and the lower surface Y of the steel lever arm when it is operated. X … Y … [2] (vii) State one method that could be used to permanently join the steel side plates to the steel lever arm. … [1] (viii) Calculate the approximate force that is available to pull the tent peg when an effort of 200 N is applied to the end of the lever arm. Include units in your answer. … … … … [3] (b) (i) Using sketches and notes, complete Fig. 10.3 to show a beam supported by walls A and B. A B Fig. 10.3 [2] (ii) Using sketches and notes, complete Fig. 10.4 to show a tie at joint C. C Fig. 10.4 [2] (iii) Using sketches and notes, complete Fig. 10.5 to show a strut at joint D. D Fig. 10.5 [2] (c) Fig. 10.6 shows the layout of timber in the base of a small wooden building. spacing pieces Fig. 10.6 (i) Give two features of the timber used in the layout that will affect performance of the structure. 1 … 2 … [2] (ii) Give two reasons for using the spacing pieces in Fig. 10.6. 1 … 2 … [2] (iii) Use sketches and notes to show one way of securing the spacing pieces in position. List any fixings that will be used. [3]

25 marks

Mark scheme: 10(a)(i) First order lever 1 10(a)(ii) Feature A is a gusset plate 1 10(a)(iii) Feature A is used to support the joints between the 1 Award marks for understanding shown. baseplate and side supports. 10(a)(iv) If the ground is soft and if there were no baseplate the 2 Allow any other valid points. device would sink into the ground [1] Explanation to include any two valid points, 2 marks. The baseplate provides a larger surface area which is less Award 2 marks for a full explanation of a single point. likely to sink when pressure is applied to the lever arm [1] Efficiency of the peg puller is improved [1] The baseplate acts as a fulcrum [1] 10(a)(v) The force acting on the ground is compression. 1 10(a)(vi) The force acting on surface X is tension [1] 2 The force acting on surface Y is compression [1] 10(a)(vii) Welding is used to join the steel side plates to the steel 1 Allow brazing. Do not allow riveting. lever arm. 10(a)(viii) force  130 = 200  1500 [1] 3 Award 3 marks for correct answer with no working. force = 300000 / 130 [1] force = 2307.7 N [1] 10(b)(i) Accurately sketch / notes [1] 2 Proportions suitable [1] 10(b)(ii) Accurately sketch / notes / drawn in correct position [1] 2 If both strut and tie are shown 1 mark only Proportions suitable [1] 10(b)(iii) Accurately sketch / notes / drawn in correct position [1] 2 No mark for strut drawn with a single line. Proportions suitable [1] If both strut and tie are shown 1 mark only 10(c)(i) Features affecting performance will include: 2 Accept valid alternatives. • Knots • Shakes • Splits • Twisting • Finish or treatment needed on the timber [2  1] 10(c)(ii) The spacing pieces will: 2 • Help to prevent twisting / warping of the joists [1] • Provide extra support to floor [1] • Maintain spacing between joists. [1] [2  1] 10(c)(iii) The spacing pieces are staggered across the width to allow 3 Example method screws / nails to be fitted. • Functional method [1] • Clear sketch / notes showing method [1] • List of fixings screws / nails / joist hangers [1] • Mechanical joint used / mortise and tenon / bridle joint.[1]

This question in 0445/43 Oct/Nov 2025

11 Fig. 11.1 shows an air compressor driven by an electric motor. electric motor air compressor vee belt Fig. 11.1 (a) The electric motor uses a vee belt to connect to the air compressor. (i) Name two other types of belt that could be used. 1 … 2 … [2] (ii) Explain why the vee belt is the most suitable method of connecting the electric motor to the air compressor. … … … [2] (b) Fig. 11.2 shows the main moving parts of the air compressor. expanding rings used to form a tight seal B 50 diameter 12.5 12.5 B Fig. 11.2 (i) Use words from the list below to complete the description of the air compressor operating. Not all of the words will be used. bearing connecting crankshaft cylinder gear piston pulley The vee … transfers motion to the … causing it to rotate. This in turn causes the … rod to move the … . [4] (ii) Name the type of mechanism used to convert motion in the air compressor. … [2] (iii) Calculate the volume of air that is displaced for each rotation of part B. The formula for the area of a circle is A = π r2. … … … … mm3 [3] (c) (i) Fig. 11.3 shows the small oil holes used to lubricate the plain bearings. oil holes plain bearings Fig. 11.3 Explain why grease would not be suitable for lubricating the plain bearings. … … … [2] (ii) Name two alternative types of bearing that could have been used. 1 … 2 … [2] (iii) Give one practical benefit of using plain bearings in the compressor. … … [1] (d) Fig. 11.4 shows two hexagonal head bolts of the same length, diameter and material. 1.5 0.75 A B Fig. 11.4 (i) Give one difference that will be noticed when fitting the bolts into a threaded hole. … [1] (ii) Explain why bolt B, which has a smaller thread pitch, will resist higher torque when being tightened. … … … [2] (e) Fig. 11.5 shows a gear system. motor speed = 850 rpm motor 30t 40t 15t Fig. 11.5 (i) State the velocity ratio of the worm gear and 30t gear. … [1] (ii) Calculate the speed of the 40t gear when the motor is turning. … … … … [3]

25 marks

Mark scheme: 11(a)(i) Other types of belt could be flat, toothed or round. 2 Accept ‘plain belt’. Sketches must be identified with a name for mark to be [2  1] awarded. 11(a)(ii) Reasons for the vee belt being most suitable are: 2 Allow any other valid points. • Transmit power very well Explanation to include any two valid points, 2 marks. • Limited slip between belt and pulleys / high friction force Award 2 marks for a full explanation of a single point. • Low noise and vibration levels • Easy to install and maintain. 11(b)(i) The vee pulley transfers motion to the crankshaft causing it 4 1 mark for each word correctly used to rotate. This in turn causes the connecting rod to move the piston . [4  1] 11(b)(ii) Crank [1] / slider [1] mechanism. 2 11(b)(iii) Area of piston = Π r2 = 3.142  252 = 1963.75 (1963.495 on 3 Award 3 marks for correct answer with no working. calculator) [1] Throw of piston = 12.5  2 = 25 [1] Volume displaced = 1963.75  25 = 49093.75 mm3 or 49 087.39 [1] 11(c)(i)) Grease would not be suitable because: 2 Allow any other valid points. • It is too thick / viscous to flow through the oil holes. Explanation to include any two valid points, 2 marks. • The bearing also uses oil to carry away any particles Award 2 marks for a full explanation of a single point. from the bearing. • Grease would keep the particles in the bearing, allowing metal to metal contact. 11(c)(ii) Roller or ball bearings could have been used. 2 Accept needle bearings [2  1] 11(c)(iii) Benefits of plain bearings include: 1 Allow any other valid points. • Smaller diameter • Low maintenance • Plain bearings support higher loads. 11(d)(i) Differences in use include: 1 AOVR • More difficult to start bolt B in threaded hole / nut • Easier to start bolt A in threaded hole • Easy to cross thread bolt B when inserting • More turns needed to move bolt B through a set linear distance • Faster to insert bolt A. 11(d)(ii) • The core diameter of bolt B is larger than for bolt A due 2 Allow any other valid points. to smaller pitch and lower depth of thread Explanation to include any two valid points, 2 marks. • Larger diameter will have greater resistance to shear Award 2 marks for a full explanation of a single point. forces • Higher torque can be applied before the bolt will fail / shear. • More precise in transmitting motion 11(e)(i) The velocity ratio of the worm gear is 30:1 1 11(e)(ii) Worm gear ratio 30:1 15 t:40 t ratio 2.666:1 [1] 3 Allow ecf from (d)(ii). Total reduction ratio = 30  2.666 = 80:1 [1] Speed of 40 t gear = 850 / 80 = 10.625 rpm [1] Award 3 marks for correct answer with no working.

This question in 0445/43 Oct/Nov 2025