A trolley starts from rest at the top of a ramp. Its gravitational potential energy decreases by 45 J as it moves to the bottom. During this motion, 9 J is transferred to thermal stores. What is the kinetic energy of the trolley at the bottom?
9 J9\ \mathrm{J}9 J
45 J45\ \mathrm{J}45 J
36 J36\ \mathrm{J}36 J
54 J54\ \mathrm{J}54 J
121 exam-style questions on Edexcel GCSE Physics 3.1 Energy stores and calculations, covering 3.1.1 Gravitational potential energy, 3.1.2 Kinetic energy, and 3.1.3 Energy transfers and conservation of energy. Each one has a worked solution and a mark scheme showing where the marks go.