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Homework Help: Harmonic frequency

  1. Aug 24, 2010 #1
    1. The problem statement, all variables and given/known data

    The second harmonic frequency on a stretched wire, with a tension of 50 N and a mass per unit length density of 0.025 kg m-1, is measured to be 200 Hz. What is the length of the wire?

    2. Relevant equations

    3. The attempt at a solution
    As far as i've discovered i must find L, but i am not sure if this is the correct formula:

    In case it is correct, then what is the relation between mass, frequency,tension and length.

    If it is not, then what formula i should use in order to get length?

    I searched throughout google, but i couldn't find any other formulas. Totally confused:/
  2. jcsd
  3. Aug 25, 2010 #2
    Re: Length?

  4. Aug 25, 2010 #3
    Re: Length?

    Hi. The velocity of the propagating wave [tex]v=\sqrt{\frac{T}{u}}[/tex] where [tex]{u}[/tex] is the mass per unit length.

    In the second harmonic frequency, [tex]\lambda = L[/tex].

    Use [tex]v=\lambda{f}[/tex] to solve the rest.
    Last edited: Aug 25, 2010
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