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Homework Help: Statistical mechanics question

  1. Sep 24, 2006 #1
    Below 0.6K the heat capacity of liquid He is well represented by the equation
    Cv=(9.819 x 10^-3 K^-3)NkT^3
    Given that transverse shear waves cannot propagate in a liquid, predict the phonon contribution to the heat capacity of He from the data
    c=238 m/s (speed of sound in liquid He)
    p=0.145 g cm^-3 (density of liquid He)

  2. jcsd
  3. Sep 24, 2006 #2
    x is supposed to be multiplication
    N number of molecules
    k Boltzmann's constant
    T temperature in kelvin
    Cv heat capacity
  4. Sep 25, 2006 #3
    I find this rather hard to follow since I'm not getting that the specific heat has a T^3 dependence at low temperatures for a system of massless bosons (read: the phonons). I'm getting that U ~ T^3 and, then C_v ~ T^2, so I'm a little confused. I also haven't slept much the past two weeks so I could be doing something silly here.
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