# A swimming pool appears shallower than it actually is when viewed from above the water surface. Use your knowledge of refraction to explain why the pool appears shallower than its true depth.

> Eduqas A-Level Physics — 2.6 Refraction of light · Explain · 5 marks

> Light from the bottom of a swimming pool travels upward through the water and then passes into the air above.

## Mark scheme (5 marks)

1. Light travels from water into air (at the water surface / boundary)
2. Light changes direction / bends away from the normal as it enters the less dense medium (air)
3. The observer's eye traces the refracted ray back in a straight line
4. This straight-line trace meets the bottom of the pool at a point that is higher / closer to the surface than the actual bottom
5. Therefore the pool appears shallower than its true depth

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Physics](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-swimming-pool-appears-shallower-than-844e0974) · Published by Druglandscape Ltd.