Practical: investigate the specific heat capacity of a substance
3 marks · EasyA student wants to find the specific heat capacity of a 0.5 kg block. The electric heater supplies energy for 400 s. The current is 3.0 A and voltage is 12 V. The temperature rise is 16 °C.
Calculate the energy supplied by the heater.
Calculate the specific heat capacity of the block.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) 14,400 J
(b) 1,800 J/kg °C
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Calculates energy: V × I × t = 12 × 3 × 400 = 14,400 J
M2 (b) · 1 mark · Uses c = energy / (m × Δθ) in correct substitution (follow-through)
A1 (b) · 1 mark · Final answer for specific heat capacity is 1,800 J/kg °C (follow-through)
Worked solution
a) Energy supplied = V × I × t = 12 × 3.0 × 400 = 14,400 J. b) Specific heat capacity: c = energy / (m × Δθ) = 14,400 / (0.5 × 16) = 14,400 / 8 = 1,800 J/kg °C.