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Homework Help: Wave problem

  1. Sep 3, 2006 #1

    The equation of a certain traveling transverse wave is
    y(x,t)=4.00sin(81.0(pi)t - 1.590(pi)x) where t is in seconds and x and y are in cenimeters. Find the speed of propagation, the period and the wavelength for these waves (express you answer in units of m/s)

    So, I know A (amplitude) is 4.00cm....0.04m and the angular frequency is 81.0pi rad/s and k=1.590pi . To find the speed of propagation i divided angular frequency by k and got 50.94, but i don't know if that cm/s or not since the whole equation is based in cm. I can find the other values too, but I am not sure if I need to convert my answers.
  2. jcsd
  3. Sep 3, 2006 #2

    Andrew Mason

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    Convert distances to metres and rewrite the equation:

    [tex]y(x,t)=4.00\sin{81.0\pi t} - (1.590\pi)(100x)[/tex]

    [itex] k = 159\pi m^{-1}[/itex] Speed of the wave is [itex]\omega/k[/itex] in [itex]sec^{-1}/m^{-1} =\text{m/sec.}[/itex]
    Last edited: Sep 3, 2006
  4. Sep 3, 2006 #3
    I got:

    v= 0.509 m/s (omega/k)

    T= 0.0247 s (1/f = 2pi/omega)

    wavlength= 0.0126 m (2pi/k)
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