Measuring heat energy
3 marks · NormalA 250 g block of copper is heated from 20 °C to 50 °C. The specific heat capacity of copper is 390 J/kg°C. Calculate the amount of energy supplied.
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2,925 J (±5)
Must show: substitution, calculation
Also accept: 2.93 kJ
Common mistakes: Forgetting to convert g to kg; Using wrong formula
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Marking points
M1 · 1 mark · Use and substitute values (0.25 kg, 390 J/kg°C, 30°C).
A1 · 1 mark · Correct conversion from g to kg and temperature change.
A2 · 1 mark · Correct calculation: final answer 2925 J (accept 2930 J) with working shown.
Worked solution
First, convert mass to kg: 250 g = 0.25 kg
= 0.25 390 (50 - 20)
= 0.25 390 30
= 0.25 11,700
= 2,925 J