# A student estimates the volume of air in a classroom. Describe how the student could make a reasonable estimate of the volume of air in the classroom, and explain how they decide whether their answer is a sensible order of magnitude.

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

> Estimating physical quantities is an important skill in physics. A typical classroom is used as an example.

## Mark scheme (5 marks)

1. Identifies that the classroom can be approximated as a cuboid (or rectangular box)
2. States that length, width, and height of the room must each be estimated
3. Gives a reasonable estimate for at least one dimension (e.g. length 8–12 m, width 6–10 m, height 2.5–4 m)
4. States that volume is calculated by multiplying length × width × height
5. Explains that the estimate is sensible if it is the correct order of magnitude (e.g. hundreds of cubic metres, not thousands or tens), by comparing it to a known quantity or everyday experience

## 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 "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-estimates-the-volume-of-a3b27993) · Published by Druglandscape Ltd.