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Wave Motion On A String

  1. Dec 10, 2008 #1
    1. The problem statement, all variables and given/known data

    A wave travels along a string at a speed of 261 m/s. What will be the speed if the string is replaced by one made of the same material and under the same tension but having twice the radius?

    2. Relevant equations

    v=squareroot(T/mu) (where T=tension)

    mu=m/L (where m= mass and L= length)

    3. The attempt at a solution

    I'm not sure how I need to manipulate mu to accomadate for twice the radius. Volume would change, but wouldn't mass as well? I thought maybe I would need to use density, but we are not given the density of the string. Do I assume the mass doesn't change because the tension is the same? Fatter strings are supposed to go slower. So I'm really stuck on what to do..Help please?!
  2. jcsd
  3. Dec 10, 2008 #2


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    Doubling the radius will change the linear density by a certain factor, which you'll need to figure out. I.e., if the radius is twice as big, then the volume (and hence mass) of a 1 m long string will be larger by what factor?
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