# A sound wave travelling through air enters a solid wall. State and explain what happens to the frequency, wavelength, and speed of the sound wave as it passes from air into the solid.

> Cambridge International IGCSE Physics (0625) — 3.1 General properties of waves · Explain · 4 marks

## Mark scheme (4 marks)

1. The frequency remains unchanged / stays the same
2. The speed increases as the wave enters the more dense solid medium
3. The wavelength increases
4. Correct reasoning linking speed and wavelength: because speed = frequency × wavelength, and frequency is constant, wavelength must increase when speed increases

## Key terms

- [frequency](https://www.gradenine.co.uk/glossary/frequency)
- [wavelength](https://www.gradenine.co.uk/glossary/wavelength)
- [speed](https://www.gradenine.co.uk/glossary/speed)

## Related

- [Revision notes for Cambridge International IGCSE Physics (0625)](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-sound-wave-travelling-through-air-6241fd37) · Published by Druglandscape Ltd.