Pearson Edexcel International GCSE (9–1) · PHYSICS · Section
Power
18 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
5 marks · Hard
Answer and see the solution →A passenger lift of mass 800 kg carries 5 people each of mass 60 kg to a height of 18 m in 22 s. Assume the upward force from the cables exactly balances the total weight as the lift moves at constant speed.
(a)[1 mark]Calculate the total weight lifted by the cables.
(b)[2 marks]Calculate the work done on the lift and passengers in raising them to the top floor.
(c)[2 marks]Calculate the power developed by the lift motor.
Question 2
4 marks · Hard
Answer and see the solution →A bungee jumper leaps from a bridge, attached securely to an elastic cord. Describe in detail how energy is transferred between stores from the moment the jumper steps off the platform until the lowest point of the jump, including where energy is not conserved as useful energy. Refer to named energy stores and describe at least three distinct transfers in your answer.
Question 3
5 marks · Hard
Answer and see the solution →A 0.25 kg ball is dropped from a balcony 25 m above the ground. Ignore air resistance.
(a)[2 marks]Calculate the gravitational potential energy lost by the ball as it falls.
(b)[2 marks]Determine the speed of the ball just before it hits the ground.
(c)[1 mark]Explain why, in real life, the ball’s speed might be less than your calculation.