A prototype wave-energy converter converts 12.5% of the incident wave energy it receives into useful electrical energy.
Calculate the total wave energy, in megajoules (MJ\text{MJ}MJ), that must be incident on the converter to generate 4.5 MJ4.5\text{ MJ}4.5 MJ of useful electrical energy.
38 exam-style questions on Edexcel GCSE Physics 3.2 Dissipation and efficiency. Each one has a worked solution and a mark scheme showing where the marks go.