In a car, the engine transfers energy to the gearbox, and the gearbox transfers energy to the wheels.
The efficiency of the engine is 0.30. The efficiency of the gearbox is 0.90.
During a short journey, the fuel supplies 500 kJ of energy to the engine.
Calculate the useful energy transferred from the engine to the gearbox.
Calculate the overall efficiency of the car, from the energy supplied by the fuel to the energy transferred to the wheels.
Explain why the overall efficiency is lower than the efficiency of the engine or the gearbox on its own.
Explain one way that the efficiency of the gearbox could be increased.
100 exam-style questions on Edexcel GCSE Physics 3.2 Dissipation and efficiency, covering 3.2.1 Dissipation of energy, 3.2.2 Reducing unwanted energy transfers, 3.2.3 Efficiency, and 3.2.4 Increasing efficiency. Each one has a worked solution and a mark scheme showing where the marks go.