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AQA · GCSE · Physics · Higher

Nuclear Station Energy Output

Q02.3 3 marks
energy transferred = power × time, E=PtE = Pt

A nuclear power station has a power output of 500 MW.

Calculate the energy output in 3600 s.

Give your answer in J.

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Marking points

  1. 1 Converts 500 MW to 500 000 000 W.
  2. 2 Uses E = Pt with 3600 s.
  3. 3 Obtains 1.8 × 10^12 J (subject to official error-carried-forward guidance).

Full-mark answer

500 MW=5.00×108 W500\text{ MW}=5.00\times10^8\text{ W}. Therefore \(E=Pt=(5.00×10^8)(3600)=1.8×10^{12}text{ J}\).

Why this answer loses marks

I multiplied the power value by the time without converting the power.

The time is in seconds and the answer is required in joules, so convert the power into compatible units before applying E = Pt.

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