Study Hack Lab

RP 1Physics

Specific heat capacity

Write-up template

Name
Date
Course: GCSE Physics
Board and specification: AQA GCSE Physics (8463), 4.1.1.3AQA GCSE Combined Science: Trilogy (8464), 6.1.1.3Apparatus and techniques: AT 1, AT 5
Class and teacher

Aim

Determine the specific heat capacity of a metal block by heating it electrically, measuring the energy transferred to it and its temperature rise.

Plan and risk assessment
Apparatus
Method
Results
Graph
Analysis
Conclusion and evaluation
Make safe and clear up

A blank write-up for use in a real lesson. The headings follow the AQA required practical; the readings are yours to take. Layout v1, practical v2. Original material; not affiliated with AQA, which has not reviewed it.

1 Plan and risk assessment

The specific heat capacity of a material is the energy needed to raise the temperature of 1 kg of it by 1 °C. Heat a block electrically, measure the energy with a joulemeter and the temperature rise with a thermometer, and c = ΔE ÷ (m Δθ).

ΔE = m c Δθ

Variables

Independent (you change)
Dependent (you measure)
Control (you keep the same)

Prediction

Predict how the temperature of the block will change as energy is transferred to it.

Predict whether your value of c will be higher or lower than the data-book value.

A 1 kg block of aluminium and a 1 kg block of copper each receive the same amount of energy from a heater. Predict which block warms up more.

Risk assessment

Hazard	Harm it could cause	Control

2 Apparatus

1 kg metal block with two holes The material being tested.
Top-pan balance (resolution 0.1 g) Measures the mass of the block.
Immersion heater (12 V) Transfers energy into the block.
Thermometer (−10 to 110 °C) (resolution 1 °C) Measures the temperature of the block. Its scale is marked every 1 °C; read it to the nearest 0.5 °C, halfway between two marks.
Joulemeter (resolution 1 J) Measures the energy transferred by the heater.
Low-voltage power supply Powers the heater.
Pipette and water A few drops in the thermometer hole for good thermal contact.
Insulation jacket Reduces energy transfer to the surroundings.
Stopwatch Times the readings.
Heatproof mat Protects the bench from the hot block and heater.

3 Method

Write numbered steps someone else could follow. Say what you measure, with which instrument, and how you keep it a fair test.

4 Results

The table is drawn before you measure. Record each reading to the resolution of the instrument, then work out the mean of your repeats, leaving out any anomaly.

Heating the block · Read the joulemeter and the thermometer at the same moment, every 60 s.

Time in s	Energy transferred in J	Temperature in °C
0
60
120
180
240
300
360
420
480
540
600

Anomalies

Ring any anomalous result. Say what probably went wrong and whether you repeated it.

5 Graph

Temperature against energy transferred · Choose your axes: the independent variable goes on the x-axis. Label each axis with the quantity and unit.

6 Analysis

Mass of the block
1 kg = 1000 g
Answer
Gradient (temperature rise per joule)
Answer
Specific heat capacity
ΔE = m c Δθ, so c = 1 ÷ (m × gradient)
Answer

7 Conclusion and evaluation

Conclusion

Conclusion: what do your results show? Use your own numbers.

Sources of error

For each, say whether it is systematic or random, and how it affected your results.

Energy transferred to the surroundings

Energy heating the heater and thermometer

Poor thermal contact around the thermometer

Reading the thermometer

Improvement

How could you improve the method? Say why it would help.

8 Make safe and clear up

Switch off the power supply as soon as the last reading is taken.
Leave the heater and block to cool on the heatproof mat; do not touch them while hot.
Take the thermometer out carefully and put it back in its rack.
Disconnect the leads from the power supply and the joulemeter.
Wipe up the water, then return the apparatus to where you collected it once it is cool.