Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Forces and Motion
367 practice questions
Topics covered
Practice questions
151–160 of 181 · Normal
Question 151
2 marks · Normal
Answer and see the solution →A person jumps off a small boat onto a pier. As she jumps forward, the boat moves backwards. Explain why the boat moves backwards using Newton's third law.
Question 152
4 marks · Normal
Answer and see the solution →In a game of tug-of-war, two teams pull on opposite ends of a rope. Both teams seem to pull with all their strength, but neither team is moving.
(a)[2 marks]Explain, using Newton’s third law, why neither team moves even though both are pulling hard.
(b)[2 marks]Describe the action and reaction forces between one team and the rope.
Question 153
1 mark · Normal
Answer and check →A person hits a nail into a piece of wood with a hammer. According to Newton’s third law, what is the force exerted by the nail on the hammer?
- A.The nail exerts a greater force than the hammer.
- B.The nail exerts an equal force to the hammer but in the opposite direction.
- C.The nail does not exert any force on the hammer.
- D.The nail exerts a smaller force because it is lighter.
Question 154
3 marks · Normal
Answer and see the solution →A student places a block on a spring scale (newton meter) hanging from a clamp stand. The block hangs at rest.
(a)[2 marks]State the action and the reaction force involved between the block and the spring scale.
(b)[1 mark]Explain, using Newton's third law, why the reading on the scale does not change while the block is hanging and at rest.
Question 155
4 marks · Normal
Answer and see the solution →A person tries to open a heavy gate by applying a force of 120 N perpendicular to the gate, 0.75 m from the hinge. Another person tries to keep the gate closed by pushing with a force of 180 N, but only 0.3 m from the hinge.
(a)[1 mark]Calculate the moment produced by the first person about the hinge.
(b)[1 mark]Calculate the moment produced by the second person about the hinge.
(c)[2 marks]State which person has a greater turning effect on the gate and explain your answer.
Question 156
4 marks · Normal
Answer and see the solution →The diagram shows a uniform beam of length 2.0 m and negligible mass balanced on two supports, A and B, at either end. A box of mass 20 kg is placed 0.5 m from support A.
Beam with supports and load (a)[1 mark]Draw a force diagram showing the forces acting on the beam.
(b)[2 marks]Taking moments about support A, calculate the upward force on support B due to the box only. (Take g = 10 N/kg.)
(c)[1 mark]State and explain how the upward forces at supports A and B would change if the box is moved closer to support B.
Question 157
1 mark · Normal
Answer and see the solution →In a uniform ruler, where does the weight act? State the name of the point.
Question 158
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 159
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 160
1 mark · Normal
Answer and see the solution →Explain the meaning of the term 'pivot' in the context of turning effects of forces.