# Doppler Effect

Frequency changes relative to the observer due to the doppler effect. Does wavelength?

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berkeman
Mentor
Frequency changes relative to the observer due to the doppler effect. Does wavelength?

The velocity of the source is not the velocity of the sound wave that you hear coming from that source. The velocity of sound in air depends on the air density, etc., but not on the velocity of the source.

So now what do you think is the answer to your question?

the wave length becomes shorter ?

berkeman
Mentor
the wave length becomes shorter ?

When the sound source is moving towards you, yes. The sound velocity itself stays the same, and the wavelength shrinks and the frequency goes up:

Velocity = Wavelength * Frequency (check the units to be sure that I'm correct on this)

If the souce of the sound is moving away from you, what happens?

http://en.wikipedia.org/wiki/Doppler_effect

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