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Homework Help: Easy Waves

  1. Mar 25, 2008 #1
    1. The problem statement, all variables and given/known data
    string is under tension 400N. A 1m string has mass 5grams. what is the speed if the wavelength is 1m. What is the speed if the wavelength is .5m. What is the frequency?

    2. Relevant equations
    v = sqrt(Tension/(m/L))
    v = f * wavelength

    3. The attempt at a solution

    a) v = sqrt(400N / (.005kg/1m) = 283m/s

    b) im confused. whether to use the first or second equation?
    v=sqrt(400N/.005kg/.5m) = 200m/s

    c) f = v/wl = 200m/.5ms = 400Hz

    is this correct?
    Last edited: Mar 25, 2008
  2. jcsd
  3. Mar 25, 2008 #2
    just a push in the right direction would be highly appreciated
  4. Mar 25, 2008 #3
    L is the entire length of the string. Why would the linear mass density, something that is inherent and doesn't change with the same string, be changing?
  5. Mar 25, 2008 #4
    so for b) would it be 1m for both, or is the speed impossible to derive from that formula?
  6. Mar 25, 2008 #5
    If [tex] V=\sqrt{\frac{T}{\mu}}[/tex]

    What do you hypothesise if mu and T are always constant?
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