# A student investigates the specific heat capacity of water by heating a known mass of water using an immersion heater and recording the temperature at regular time intervals. Describe how the student can ensure their results are as accurate and reliable as possible, and explain why it is important to stir the water throughout the experiment.

> OCR A-Level Physics A (H556) — 1.1 Practical skills assessed · Describe · 5 marks

> Specific heat capacity is the amount of energy needed to increase the temperature of one kilogram of a substance by one degree Celsius. A student uses an immersion heater, a thermometer, a joulemeter and an insulated beaker to investigate the specific heat capacity of water.

## Mark scheme (5 marks)

1. Use insulation around the beaker to reduce heat loss to the surroundings, improving accuracy of energy measurements
2. Repeat the experiment and calculate a mean temperature reading to improve reliability
3. Use a joulemeter (or record current and voltage and time) to accurately measure the energy supplied to the water
4. Stirring ensures the thermal energy is distributed evenly throughout the water so the thermometer gives a representative temperature reading
5. Temperature is a measure of the average kinetic energy of the particles, so an uneven distribution of energy would give a misleading reading of the average kinetic energy of all the water particles

## Key terms

- [specific heat capacity](https://www.gradenine.co.uk/glossary/specific-heat-capacity)
- [temperature](https://www.gradenine.co.uk/glossary/temperature)

## Related

- [Revision notes for OCR A-Level Physics A (H556)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-investigates-the-specific-heat-4d54f98e) · Published by Druglandscape Ltd.