Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Forces and Motion
367 practice questions
Topics covered
Practice questions
331–340 of 367
Question 331
1 mark · Normal
Answer and see the solution →Which change will increase the moment of a force about a given pivot?
- A.Increase the force applied.
- B.Move the force closer to the pivot.
- C.Use a lighter object.
- D.Reduce the perpendicular distance from the pivot.
Question 332
4 marks · Normal
Answer and see the solution →A uniform beam is 3.0 m long and weighs 120 N. It is supported horizontally at its two ends, P and Q. A load of 90 N is placed 2.0 m from end P.
(a)[2 marks]Taking moments about end P, calculate the upward force at support Q.
(b)[2 marks]Calculate the upward force at support P.
Question 333
1 mark · Normal
Answer and see the solution →Explain the meaning of the term 'pivot' in the context of turning effects of forces.
Question 334
4 marks · Normal
Answer and see the solution →A uniform plank of wood is 4.0 m long and has a weight of 200 N. It rests horizontally on two supports placed 0.5 m from each end.
Wooden plank supported near each end (a)[1 mark]Calculate the distance from Support 1 to the centre of gravity of the plank.
(b)[3 marks]Determine, using the principle of moments about Support 1, the upward force at Support 2.
Question 335
2 marks · Normal
Answer and see the solution →Explain why it is easier to loosen a tight bolt using a spanner with a long handle rather than a short one.
Question 336
4 marks · Normal
Answer and see the solution →A mechanic uses a wrench to loosen a bolt. The wrench is 0.30 m long, and he applies a force of 150 N perpendicular to the wrench at its end.
(a)[2 marks]Calculate the moment produced by the mechanic about the centre of the bolt.
(b)[2 marks]Explain what would happen to the moment if the mechanic applied the same force closer to the centre of the bolt.
Question 337
2 marks · Normal
Answer and see the solution →State what is meant by the 'centre of gravity' of a body, and describe how the weight of a body acts with respect to this point.
Question 338
4 marks · Normal
Answer and see the solution →A uniform horizontal rod of length 1.8 m and weight 90 N is supported at its two ends, labelled P and Q. A load of 60 N is hung from the rod, 0.3 m from end P.
(a)[3 marks]Taking moments about point P, calculate the upward force at Q.
(b)[1 mark]State the upward force at P.
Question 339
2 marks · Normal
Answer and see the solution →Diagram Force (N) Distance from pivot (m) Angle to lever arm (°) A 40 0.2 90 B 60 0.1 0 C 80 0.05 90 D 100 0.01 90 Look at the table showing different forces applied to a door at various distances and angles from the hinge (pivot).
Question 340
3 marks · Normal
Answer and see the solution →A bridge is supported at both ends. A heavy truck stops near the left end of the bridge. Explain, using the principle of moments, how the upward forces at the left and right supports change as the truck moves from the left end to the centre of the bridge.