# A camper fills a metal water bottle and a plastic water bottle with boiling water. Both bottles have the same volume of water. The camper notices that the water in the metal bottle cools down much faster than the water in the plastic bottle. Explain why the water in the metal bottle loses thermal energy to the surroundings more quickly than the water in the plastic bottle.

> WJEC A-Level Physics (Wales) — 3.4 Thermal physics · Explain · 5 marks

## Mark scheme (5 marks)

1. Metals are good conductors of thermal energy / heat
2. Thermal energy is conducted from the hot water through the metal bottle to the cooler surroundings
3. Plastic is a poor conductor / good insulator of thermal energy
4. The plastic bottle slows down / reduces the rate of thermal energy transfer to the surroundings
5. The greater the temperature difference between the water and the surroundings, the greater the rate of thermal energy transfer

## Key terms

- [thermal energy](https://www.gradenine.co.uk/glossary/thermal-energy)

## Related

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

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-camper-fills-a-metal-water-bfe31ca7) · Published by Druglandscape Ltd.