Physics 9702 · AS & A Level · Energy conservation

Energy conservation — practice question

The information shown below comes from a test carried out on a petrol engine in a motor car. power delivered: $150\,\text{kW}$ fuel used per hour: $20\,\text{litres per hour}$ fuel energy content: $40\,\text{MJ per litre}$ Which expression should be used to determine the efficiency of the engine?

  • A$\frac{150 \times 10^3}{40 \times 10^6 \times 20 \times 60 \times 60}$
  • B$\frac{150 \times 10^3 \times 60 \times 60}{20 \times 40 \times 10^6}$
  • C$\frac{150 \times 10^3 \times 40 \times 10^6 \times 20}{60 \times 60}$
  • D$\frac{150 \times 10^3 \times 20}{40 \times 10^3 \times 60 \times 60}$

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