Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Forces and Motion
367 practice questions
Topics covered
Practice questions
141–150 of 181 · Normal
Question 141
3 marks · Normal
Answer and see the solution →A cyclist and their bicycle have a combined mass of 90 kg. If their velocity changes from 6 m/s to 0 m/s in 2 seconds, calculate the average resultant force acting on them while stopping.
Question 142
4 marks · Normal
Answer and see the solution →A trolley of mass 2 kg is moving at 3 m/s towards a stationary trolley of mass 1 kg. They collide and stick together.
(a)[2 marks]Calculate the total momentum before the collision.
(b)[2 marks]Calculate the velocity of the joined trolleys after the collision.
Question 143
3 marks · Normal
Answer and see the solution →Describe and explain what happens to the momentum of two ice skaters who push off from one another on frictionless ice. Use the principle of conservation of momentum.
Question 144
3 marks · Normal
Answer and see the solution →The following table shows the mass and velocity of three objects moving in a straight line:
Object Mass (kg) Velocity (m/s) A 2.0 4.0 B 1.5 6.0 C 5.0 1.0 (a)[3 marks]Calculate the momentum of each object and complete the table below.
Question 145
1 mark · Normal
Answer and see the solution →Which statement best describes how seat belts improve passenger safety in a car crash, using ideas about momentum?
- A.They increase the force acting on the passengers.
- B.They make the change in momentum larger.
- C.They increase the time over which momentum changes, reducing the force.
- D.They prevent the car from stopping suddenly.
Question 146
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 147
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 148
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 149
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 150
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.