# wavelength of sound and windspeed

by nil1996
Tags: sound, wavelength, windspeed
 P: 291 Both source and observer are at rest. If the wind blows from source to observer will the wind affect the wavelength of sound??
 Homework Sci Advisor HW Helper Thanks PF Gold P: 10,249 Excellent question: how are attempting to answer it so far?
 P: 291 i am thinking like if the wind speed is u and sound speed is v then the observer will notice that the sound is at speed v+u. Wave length is the distance between two compressions. The wind is moving the whole medium with the speed u. So i think there will be no change in wavelength as the successive compressions will be both moving at an additional speed u. Is that right??
Homework
HW Helper
Thanks
PF Gold
P: 10,249

## wavelength of sound and windspeed

I think the issue here is what we are comparing the wavelength to.
The wavelength without the wind perhaps?
And with respect to whome?

So the source makes compressions and rarifactions with period T.
The wind whips them away ... so instead of moving at speed c, they move at speed c+v.
 P: 291 oh,got it so the wavelength should be (v+c)/f f = frequency
 P: 291 The wind takes the first compression made by the source further by c*T before the second compression is released.Right??
 Homework Sci Advisor HW Helper Thanks PF Gold P: 10,249 That's what I figured - but it's your work. What if the air was still but both source and detector were moving?

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