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Specific heat capacity and latent heat questions

Calculate heating energy, temperature rise and changes of state; analyse electrical heating and stated energy losses.

Practise

Electrical heating experiment

A heater transfers energy to a 0.2 kg block at 60 W for 26.66666667 s. The block warms by 16 °C. Ignore energy transferred to the surroundings and apparatus. Find its specific heat capacity. Give your answer to 3 significant figures.

Heater 60 W for 26.66666667 sBlock 0.2 kg; rise 16 °CHeaterProbe
Heater power 60 W for 26.66666667 s; block mass 0.2 kg and temperature rise 16 °C. Energy losses are ignored as stated in the question.
Larger diagram
Heater 60 W for 26.66666667 sBlock 0.2 kg; rise 16 °CHeaterProbe

Treat the given values as exact unless an uncertainty is stated.

Use decimals or e notation, e.g. 4.2e-3. Enter the unit separately.

Hint

Calculate E = Pt before using c = E/(mΔθ).

Worked solution
  1. E = 60 × 26.66666667 = 1600 J.
  2. c = 1600 / (0.2 × 16) J kg⁻¹ °C⁻¹.
  3. Answer: 500 J kg⁻¹ °C⁻¹ (3 significant figures).
Another question
Question type: Mixed practice
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Foundation and Higher: this set covers content common to both tiers. Some calculations need several steps.

Heating and changes of state

Use E = mcΔθ when temperature changes without a change of state. Use E = mL for a change of state at constant temperature. Specific heat capacity is measured in J kg⁻¹ °C⁻¹; specific latent heat in J kg⁻¹. Electrical input Pt may include energy transferred to the surroundings and apparatus. Only treat it as energy gained by the sample when the question states that assumption.

Work through the practical method and sample results

GCSE scope

AQA 8463: 4.1.1.3; 4.3.2.2–3; required practical 1 (selected); OCR Gateway J249: P1.2d–f; PM1.2i–ii; PAG P5 (selected). Tasks cover the selected skills listed above.

AQA specification · OCR Gateway specification