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Question about Doppler effect

  1. Mar 13, 2005 #1

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

    [tex] f= \frac {\partial {(Vs-Vo)}} {\partial {(Vs-Ve)}} f' [/tex]

    In this case, Vs=Ve, f=infinite???
  2. jcsd
  3. Mar 13, 2005 #2
    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.
  4. Mar 13, 2005 #3

    Where can i find the demonstration of doppler formula???
  5. Mar 13, 2005 #4


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    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).

  6. Mar 13, 2005 #5
    Dear Dextercious:

    Setting where???
  7. Mar 13, 2005 #6


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    In the general Doppler-Fizeau formula...

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