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Homework Help: Wavelengths and Frequency

  1. Sep 18, 2007 #1
    1. The problem statement, all variables and given/known data
    Particles approximately 3.0 x 10^-2 cm in diameter are to be scrubbed loose from machine parts in an aqueous ultrasonic cleaning bath. Above what frequency should the bath be operated to produce wavelengths of this size and smaller?

    2. Relevant equations
    Fn = nv/(2L)
    v= SQRT(F/Mew)

    3. The attempt at a solution
    So far I cannot come up with a beginning place on this one... I am thinking about using f=v/(lambada) but how would i come up with the velocity (v) without mew or F?
  2. jcsd
  3. Sep 18, 2007 #2


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    I think you just need to use: frequency = (speed of light)/wavelength

    Use wavelength = 3.0*10^-2cm = 3.0*10^-4m
  4. Sep 18, 2007 #3


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    It's an ultrasound cleaner so it's not the speed of light - it would be the speed of sound in the liquid.
    You could just quote the frequency in terms of sound speed if you don't have a value.
  5. Sep 18, 2007 #4


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    Oops. Sorry about that. :redface:
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