Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
NEWTON'S THIRD LAW: ACTION AND REACTION
16 practice questions
Practice questions
1–9 of 9 · Normal
Question 1
2 marks · Normal
Answer and see the solution →A student stands on a skateboard in a stationary position. She pushes against a wall with her hands and starts moving backwards.
(a)[2 marks]Explain, using Newton's third law, why the student moves backwards when she pushes against the wall.
Question 2
3 marks · Normal
Answer and see the solution →A book rests on a table. The weight of the book is 7 N.
(a)[2 marks]Identify the action force and the reaction force acting on the book and table.
(b)[1 mark]State the direction of each force.
Question 3
3 marks · Normal
Answer and see the solution →When a swimmer pushes water backwards with her hands while swimming, she moves forwards.
(a)[3 marks]Explain, using Newton's third law, how the swimmer is able to move forward through the water. Include a clear identification of the pairs of forces involved.
Question 4
2 marks · Normal
Answer and see the solution →State Newton’s third law of motion.
(a)[2 marks]Write out the standard statement used in your course.
Question 5
4 marks · Normal
Answer and see the solution →The diagram below shows a person (A) in a small rowboat pushing another person (B) in a second rowboat. Both boats are initially at rest.
Two boats on a lake. A (on left) is pushing B (on right). (a)[2 marks]Describe what happens to both A and B when A pushes B's boat away. Refer to the forces involved.
(b)[2 marks]Explain how this demonstrates Newton’s third law. Name the action and reaction forces.
Question 6
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 7
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 8
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 9
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.