The diagram shows the wheel wrench being used without the handle extended.

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1 Q. A company makes a wheel wrench with an extending handle. The company claims that the extending handle makes it easier to loosen the wheel nuts on a car. The diagram shows the wheel wrench being used without the handle extended. (a) (i) Use the equation in the box to calculate the moment produced by the force on the wrench. moment = force perpendicular distance from the line of action of the force to the axis of rotation Show clearly how you work out your answer. Moment =... newton metres (2) (ii) Units can be written in words or symbols. Which of the following is the unit for a moment written using symbols? Draw a ring around your answer. nm Nm nm NM () Page of 0

2 (b) The wheel nut will not move and so the handle of the wrench is extended. It is now easy to loosen the wheel nut using the same force as before. Explain why. (2) (Total 5 marks) Page 2 of 0

3 Q2. The diagram shows a father and his two children sitting on a playground see-saw. The see-saw is not moving. (a) What is the total clockwise moment of the two children about the axis of rotation? Explain the reason for your answer. (3) (b) (i) What is the clockwise moment of the boy, B, about the axis of rotation? Moment =... Nm () Page 3 of 0

4 (ii) Use the information in the diagram and the equation in the box to calculate the weight, W, of the boy, B. moment = force perpendicular distance from the line of action of the force to the axis of rotation Show clearly how you work out your answer. Weight of boy B =... N (2) (Total 6 marks) Q3. The diagram shows two buses. Bus A is empty. Bus B contains bags of sand upstairs to represent passengers. Each bus has been tilted as far as it can without falling over. (a) Each bus will topple over if it is tilted any further. Explain, in as much detail as you can, why this will happen. (You can draw on one of the diagrams as part of your answer if you want to.) (2) Page 4 of 0

5 (b) What difference does it make to the stability of the bus when the upper deck is full of passengers? Explain your answer as fully as you can (3) (c) Why are the bags of sand in bus B only put upstairs? () (Total 6 marks) Q4. A spanner makes it a lot easier to loosen a bolt. You cannot usually loosen a bolt with your fingers. It is easier with a spanner. Choose words from this list to complete the sentences below. lever piston pivot pulley turning effect The spanner is a simple... You use it to produce a bigger... on the bolt. A longer spanner works better. This is because there is a bigger distance between your force and the... (Total 3 marks) Page 5 of 0

6 M. (a) (i) 75 allow mark for correct substitution ie do not credit if subsequent step shown allow mark for an answer (ii) Nm (b) force is (applied) further from the nut / pivot / axis of rotation handle is longer is insufficient do not accept less force needed moment (on wrench) is larger [5] M2. (a) 960 (Nm) see-saw is in equilibrium accept see-saw is balanced see-saw is stationary is insufficient (total) clockwise moments = anticlockwise moment accept no resultant moment forces are balanced is insufficient an answer clockwise moments balance the anticlockwise moments gains 2 marks (b) (i) 600 (Nm) (ii) 375 (N) or their (b)(i).6 correctly calculated do not credit if (b)(i) is larger than 960 allow mark for correct substitution and transformation ie 2 [6] Page 6 of 0

7 M3. (a) idea line of action of weight/force/gravity (if drawn: a vertical line through the centre of mass) falls outside the (wheel) base (mark NOT from diagram) for mark each 2 (b) ideas that less stable/topples more easily centre of mass at a higher level so need small angle to make line of action of weight fall outside (wheel) base for mark each 3 (c) idea that this is the most unstable condition (when bus used) or this makes c. of m. as high as it is likely to be for mark [6] M4. lever turning effect pivot for mark each [3] Page 7 of 0

8 E. (a) (i) The calculation was well done with 92% of candidates achieving full marks. (ii) Just over 85% of candidates were able to identify the correct units for a moment from the list. (b) Not many candidates gained both marks for this question, mainly because they did not give a full explanation. A significant number of candidates lost marks by using careless terminology, with a considerable number of references to centrifugal force, pressure, leverage, and a few of momentum and/or weight. E2. (a) Most candidates correctly identified 960 Nm but fewer followed this with correct reasoning. Some candidates failed to score a second or third mark because the moments were not directional i.e. clockwise moments. (b) (i) This question was well answered with 80% of candidates scoring this mark. (ii) This part question proved to be a good end to the paper for the majority of candidates. Just over 7% of candidates gained both marks, few candidates scored just one mark. E3. Paper I3 This question was generally poorly answered. (a) (b) (c) Nearly all candidates compared Bus A and B rather than explaining that the vertical line through the centre of mass must be within the wheel base for the bus to remain upright. Many candidates thought the greater weight of the extra passengers upstairs would make the bus more stable. Good answers noted that the centre of mass would be higher, making it less stable, so the bus could not be tilted at such a big angle. Few candidates realised that it was to make the centre of mass as high as possible or make the bus as unstable as possible. Paper H5 (a) Many candidates failed to indicate, either in words or - equally acceptable - on a diagram, that it is the line of action of the weight, vertically through the centre of mass, which must not fall outside of the wheel-base. Page 8 of 0

9 (b) (c) This item was generally answered as well as candidates answers to (a) permitted. This was badly answered by the great majority of candidates, very few candidates referring to the need to test the most extreme situation likely to be met when the bus is in operation. Providing candidates with information at the start of the question about the point of the test would probably have resulted in better answers to this item. E4. There were many accurate answers to this recognition question. Page 9 of 0

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