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Wave intensity formula?

  1. May 30, 2012 #1
    Our physics teacher gave us a formula to calculate intensity, she didn't really specify what intensity, it should be related to sound.
    I = intensty
    A = amplitude
    P = Density
    F = frequency
    V = velocity
    pi = 3.14
    she said I = 2*(pi)^2*A^2*P*F^2*V
    I can't find anything like this in books or internet, maybe i'm bad at searching.
    I was wondering is she right and can she explain the formula? I get the simple I=P/A formula.
  2. jcsd
  3. May 30, 2012 #2
    This is the formula for the intensity of a plane wave with amplitude A, and frequency f, propagating with speed v.
    You can find a complete derivation of the formula here


    or just look up "intensity plane mechanical wave" or similar.
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