# A rubber band and a steel rod are both described as elastic materials. Explain what the term elastic means in this context, and describe how the behaviour of the rubber band differs from that of the steel rod when a gradually increasing tensile force is applied to each.

> AQA A-Level Physics (7408) — 3.4.2 Materials · Explain and Describe · 5 marks

## Mark scheme (5 marks)

1. Elastic means the material returns to its original shape/length when the force is removed
2. The steel rod obeys Hooke's Law / extension is directly proportional to force (within the limit of proportionality)
3. The rubber band does not obey Hooke's Law / extension is not proportional to force
4. The steel rod has a much greater stiffness / requires a much larger force for the same extension compared to the rubber band
5. Both materials return to their original length / shape when the force is removed (provided the elastic limit has not been exceeded)

## Key terms

- [elastic](https://www.gradenine.co.uk/glossary/elastic)
- [tensile force](https://www.gradenine.co.uk/glossary/tensile-force)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain and Describe" 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-rubber-band-and-a-steel-5b0a0a9b) · Published by Druglandscape Ltd.