Pearson Edexcel International GCSE (9–1) · PHYSICS · Chapter
Work and Power
58 practice questions
Topics covered
Practice questions
11–20 of 29 · Normal
Question 11
3 marks · Normal
Answer and see the solution →A football of mass 0.45 kg is moving at 12 m/s towards a goal.
(a)[3 marks]Calculate its kinetic energy.
Question 12
4 marks · Normal
Answer and see the solution →A student drops a metal ball bearing (mass 0.15 kg) from rest at a height of 2.5 m above the ground. Ignore air resistance.
(a)[2 marks]Calculate the gravitational potential energy of the ball bearing at the top.
(b)[1 mark]State the value of kinetic energy just before the ball hits the ground.
(c)[1 mark]Explain your reasoning.
Question 13
3 marks · Normal
Answer and see the solution →A small meteor enters Earth's atmosphere and burns up as a shooting star. It had a large kinetic energy on entry.
Question 14
1 mark · Normal
Answer and check →Which of the following objects has the greatest kinetic energy?
- A.A 50 kg child running at 4 m/s
- B.A 10 kg bicycle moving at 12 m/s
- C.A 1 kg ball thrown at 20 m/s
- D.A 70 kg adult jogging at 2 m/s
Question 15
3 marks · Normal
Answer and see the solution →A golf ball (mass 0.045 kg) leaves the club at a speed of 38 m/s.
(a)[3 marks]Calculate the kinetic energy of the golf ball.
Question 16
3 marks · Normal
Answer and see the solution →Explain, using the relationship for kinetic energy, why a small increase in speed leads to a much larger increase in kinetic energy.
Question 17
4 marks · Normal
Answer and see the solution →A small electric motor raises a 2.0 kg mass vertically upwards a distance of 8.0 m in 6.0 s.
(a)[2 marks]Calculate the work done by the motor in raising the mass.
(b)[2 marks]Calculate the power output of the motor during this time.
Question 18
2 marks · Normal
Answer and see the solution →Explain why, as a rollercoaster descends from the highest point to the lowest, its gravitational potential energy decreases while its kinetic energy increases.
Question 19
1 mark · Normal
Answer and check →Which statement best describes the unit of power?
- A.One joule transferred per second
- B.One newton per second
- C.One metre per second
- D.One kilogram per second
Question 20
3 marks · Normal
Answer and see the solution →A lift with passengers has a combined weight of 3500 N. The lift rises vertically at a constant speed of 2.5 m/s.
(a)[1 mark]State the upward force needed to keep the lift moving at constant speed.
(b)[2 marks]Calculate the power output of the lift motor.