# Explain how a student could estimate the volume of a human lung, giving a reasonable final value with an appropriate order of magnitude.

> AQA A-Level Physics (7408) — 3.1.3 Estimation of Physical Quantities · Explain · 5 marks

## Mark scheme (5 marks)

1. Recognise that the volume of air breathed out in one breath (tidal volume) can be measured or estimated
2. Describes a practical method — e.g. breathing into an inverted water-filled container or measuring how much a balloon expands
3. States that multiple readings (e.g. several breaths) should be taken and an average calculated to reduce uncertainty
4. Recognises that the lung volume is larger than a single tidal breath — total capacity is approximately 5–6 times a resting tidal breath, or uses a forced full breath
5. States a reasonable final value for total lung volume in appropriate units — approximately 3–6 litres (3000–6000 cm³ / 0.003–0.006 m³)

## Key terms

- [order of magnitude](https://www.gradenine.co.uk/glossary/order-of-magnitude)
- [volume](https://www.gradenine.co.uk/glossary/volume)

## Related

- [Revision notes for AQA A-Level Physics (7408)](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/explain-how-a-student-could-estimate-8e96a230) · Published by Druglandscape Ltd.