Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
THE TURNING EFFECT OF FORCES
24 practice questions
Practice questions
11–20 of 24
Question 11
1 mark · Normal
Answer and see the solution →In a uniform ruler, where does the weight act? State the name of the point.
Question 12
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 13
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 14
1 mark · Normal
Answer and see the solution →Explain the meaning of the term 'pivot' in the context of turning effects of forces.
Question 15
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 16
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 17
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 18
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 19
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 20
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).