# A guitar string is plucked and vibrates in simple harmonic motion. Explain what is meant by simple harmonic motion and describe how the acceleration and displacement of the vibrating string are related throughout one complete oscillation.

> Eduqas A-Level Physics — 5.1 Simple harmonic motion · Explain · 5 marks

> When a guitar string is plucked, it vibrates back and forth about its equilibrium position. The vibration gradually dies away as energy is transferred to the surroundings.

## Mark scheme (5 marks)

1. Simple harmonic motion involves oscillation/vibration about an equilibrium position
2. There is a restoring force that always acts towards the equilibrium position
3. Acceleration is proportional to displacement (from equilibrium)
4. Acceleration is directed towards the equilibrium position / in the opposite direction to displacement
5. At the equilibrium position, displacement is zero so acceleration is zero / at maximum displacement, acceleration is maximum

## Key terms

- [simple harmonic motion](https://www.gradenine.co.uk/glossary/simple-harmonic-motion)
- [displacement](https://www.gradenine.co.uk/glossary/displacement)
- [acceleration](https://www.gradenine.co.uk/glossary/acceleration)

## 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-guitar-string-is-plucked-and-9aa328ce) · Published by Druglandscape Ltd.