Practice question · Multiple choice
When a wave passes from one medium to another its frequency stays the same but its wavelength changes. Why is frequency the quantity that survives?
Hints
- Count crests arriving at the boundary per second and crests leaving.
- Could they differ without crests piling up at the interface?
Show the answer
A. Because it is set by the source and cycles cannot be lost
Why
Crests cannot accumulate at an interface. With and fixed, a change in speed must appear in the wavelength, which is what refraction is.
Practise Wave Properties and the Wave Equation
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More questions on Wave Properties and the Wave Equation
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