# A student watches ripples spreading out across the surface of a pond after a stone is dropped into the water. The student notices that a small floating leaf does not move across the pond, even though the ripples pass through it. Describe what is meant by a wave, and use this to explain why the leaf does not travel across the pond.

> Eduqas A-Level Physics — 2.4 The nature of waves · Describe · 5 marks

## Mark scheme (5 marks)

1. A wave is a transfer of energy (not matter/particles)
2. The water particles (or leaf) do not travel with the wave / are not carried along permanently
3. The water particles (and therefore the leaf) vibrate / oscillate up and down
4. The direction of vibration is perpendicular (at right angles) to the direction the wave travels
5. After the wave has passed, the leaf returns to its original position / the leaf ends up in the same place

## Key terms

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

## 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-watches-ripples-spreading-out-70f84f96) · Published by Druglandscape Ltd.