Conservation of energyAQA A-Level Physics: Mind map

Exam questions on Conservation of energy

1. A ball of mass 0.15 kg is released from rest at a height of 3.2 m above a hard floor. Ignore air resistance until the ball hits the floor. Take g = 9.81 N kg⁻¹.
   The ball rebounds from the floor to a height of 2.4 m. Calculate the energy dissipated in the impact with the floor.2 marks
2. A pendulum bob of mass 0.50 kg is held at rest with the bob 0.20 m above the lowest point of its swing, then released. Assume that air resistance and friction at the pivot are negligible. Take g = 9.81 N kg⁻¹.
   A second bob of mass 1.0 kg is released from the same height. Explain, using energy, why its speed at the lowest point is the same as that of the first bob.2 marks
3. A skier of mass 70 kg starts from rest at the top of a straight ski slope that is 600 m long and has a vertical drop of 150 m. At the bottom of the slope the skier is moving at 20 m s⁻¹. Take g = 9.81 N kg⁻¹.
   Explain what happens to the gravitational potential energy lost by the skier.3 marks