A spring initially stores 5.0 J. It launches a trolley along a horizontal track and finishes unstretched. During launch, 0.80 J is transferred to thermal stores. The trolley then loses a further 1.2 J to thermal stores. It started at rest. What fraction of the initial spring energy remains in the kinetic store of the trolley?
0.600.600.60
0.400.400.40
0.240.240.24
0.840.840.84
115 exam-style questions on Edexcel GCSE Physics 8.1 Energy transfers and work, covering 8.1.1 Energy stores and transfer diagrams, 8.1.2 Ways of changing a system's energy, and 8.1.3 Work done by forces. Each one has a worked solution and a mark scheme showing where the marks go.