1. Mar 13, 2005

Raparicio

Hello.

I have a question on Doppler effect. When the wave has the same velocity that the emisor, u have this:

$$f= \frac {\partial {(Vs-Vo)}} {\partial {(Vs-Ve)}} f'$$

In this case, Vs=Ve, f=infinite???

2. Mar 13, 2005

Timbuqtu

Theoretically, yes. When the emitter travels at the speed of sound, the emitted waves travel along with the emitter and therefore the wavelength will go to zero. So f = Vs/wavelength goes to infinity. That's why you here a blast when a jet reaches sound speed.

3. Mar 13, 2005

Raparicio

d

Where can i find the demonstration of doppler formula???

4. Mar 13, 2005

dextercioby

There's an elegant proof for the Doppler-Fizeau formula in electrodynamics books.I'm sure that setting "c"----"v_{sound}" & making approximations u can find the nonrelativistic cases...All 4 of them (in the case of leght,there are only 2).

Daniel.

5. Mar 13, 2005

Raparicio

Dear Dextercious:

Setting where???

6. Mar 13, 2005

dextercioby

In the general Doppler-Fizeau formula...

Daniel.