A ball is dropped onto a hard floor. The ball bounces, but it does not rise back to the height it was dropped from.
Which statement explains this?
Some energy is destroyed when the ball hits the floor, so less energy is left
Some energy is dissipated by sound and to the thermal stores of the ball and floor
The force of gravity on the ball takes some of its energy away as it falls
All of the energy in the kinetic store of the ball is transferred to the floor
50 exam-style questions on OCR GCSE Physics 7.2 Power and efficiency, covering 7.2.1 Dissipation of energy, 7.2.2 Energy transfers in domestic devices, 7.2.3 Power ratings of domestic appliances, 7.2.4 Efficiency of energy transfers, 7.2.5 Ways to increase efficiency, 7.2.6 Reducing unwanted energy transfers, and 7.2.7 Thermal conductivity and the cooling of buildings. Each one has a worked solution and a mark scheme showing where the marks go.