# A student plucks a string on a guitar, producing a wave that travels along the string. Describe what is meant by the amplitude, wavelength and frequency of a wave, and explain how increasing the frequency of a wave affects its wavelength when the wave speed stays the same.

> Eduqas A-Level Physics — 3.1 Wave properties · Describe · 5 marks

## Mark scheme (5 marks)

1. Amplitude is the maximum displacement of a point on the wave from its rest/equilibrium position
2. Wavelength is the distance between two successive points that are in phase / the length of one complete wave cycle
3. Frequency is the number of complete waves (cycles) passing a point per second / produced per second
4. Correct use of wave speed equation: wave speed = frequency × wavelength (v = f λ), stating that if speed is constant and frequency increases, wavelength must decrease
5. Clear qualitative explanation that wavelength decreases because the two quantities are inversely proportional (at constant wave speed)

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Physics](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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-plucks-a-string-on-6cf4d893) · Published by Druglandscape Ltd.