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Physics · 2.2.2 Specific heat capacity · Paper 6 practical

Specific Heat Capacity. Heat it.

Use an electric immersion heater to warm a metal block. Measure the electrical energy supplied and the temperature rise, then calculate c = E / (m Δθ). Insulation and stirring reduce heat losses.

0625 Topic 2.2.2 — Specific heat capacity Topic 4.4 — Electrical energy E = Pt Paper 6 — ATP
Setup — choose a material, then switch on the heater and start the timer.
00:00
θ 20.0 °C · Energy 0 J

Shortcuts Space heater on/off · Enter record · R reset.

Variables

—
1.0
50
70%

Live readouts

Heater power P
50 W
Energy supplied E = Pt
0 J
Temperature θ
20.0 °C
Temp rise Δθ
0.0 °C
Computed c = E/(mΔθ)
— J/kg·°C
True c
900 J/kg·°C
Heat losses make the measured c slightly larger than the true value — improve with insulation & a lid.

Trial data — θ vs energy

Switch on the heater and press Record at intervals.

θ vs E — gradient = 1/(mc)

📋 Method (Cambridge ATP procedure)
  1. Measure the mass m of the metal block on a balance.
  2. Insert the immersion heater and thermometer into the holes in the block; add a drop of oil for good thermal contact.
  3. Wrap the block in insulation and record the starting temperature.
  4. Switch on the heater and start the stopwatch simultaneously. Note the power P (or measure V and I, so P = VI).
  5. Heat for a measured time t; the energy supplied is E = Pt.
  6. Switch off, stir/wait for the temperature to stabilise, and record the final temperature.
  7. Calculate c = E / (m Δθ) = Pt / (m Δθ).

Graphical method: plot θ against E. The gradient is 1/(mc), so c = 1 / (m × gradient).

⚠ Sources of error & precautions
  • Heat loss to surroundings — lag the block with insulation and use a lid; this is why measured c > true c.
  • Heat retained by the heater — some energy heats the heater itself, not the block.
  • Thermometer contact — use oil in the thermometer hole for good thermal contact.
  • Uneven heating — wait for the temperature to stabilise before the final reading.
  • Reaction time — start the timer and heater together.
🧪 Apparatus list
  • Metal block with holes for heater and thermometer
  • 12 V electric immersion heater
  • Joulemeter or ammeter + voltmeter + stopwatch
  • Thermometer (± 1 °C), balance, insulation, low-voltage supply
🎯 Syllabus reference (0625)
  • 2.2.2 Specific heat capacity — define specific heat capacity; recall and use E = mcΔθ; describe an experiment to measure the specific heat capacity of a solid or liquid.
  • 4.4.1 Energy & power — recall and use E = Pt and P = IV.

Ask the lab assistant