# A student sets up a stretched string fixed at both ends and plucks it to produce a stationary wave. Explain how the stationary wave is formed and describe the difference between a node and an antinode.

> AQA A-Level Physics (7408) — 3.3.1 Progressive and Stationary Waves · Explain · 5 marks

## Mark scheme (5 marks)

1. Two waves (of the same frequency/wavelength) travel in opposite directions along the string
2. The two waves overlap (superpose/interfere) to produce the stationary wave
3. A node is a point of zero displacement / the string does not vibrate at a node
4. An antinode is a point of maximum displacement / the string vibrates with maximum amplitude at an antinode
5. Nodes and antinodes are fixed in position / energy is not transmitted along the string (the wave does not travel)

## Key terms

- [stationary wave](https://www.gradenine.co.uk/glossary/stationary-wave)
- [node](https://www.gradenine.co.uk/glossary/node)
- [antinode](https://www.gradenine.co.uk/glossary/antinode)

## Related

- [Revision notes for AQA A-Level Physics (7408)](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-student-sets-up-a-stretched-abf7184e) · Published by Druglandscape Ltd.