What are waves?
2 marks · NormalExplain why dropping a stone in a pond creates ripples that spread outwards but the water itself does not move away from the centre.
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Common mistakes: assuming water moves outwards with the wave
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Marking points
B1 · 1 mark · States that waves transfer energy, not matter
B1 · 1 mark · States that water particles move up and down or vibrate in place, not away from the centre
Worked solution
The ripples are waves that carry energy outward from where the stone hits, but the water particles only move up and down (they vibrate in place); they do not move outward with the wave.