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Homework Help: String Tension not sure on the answer i have.

  1. May 26, 2010 #1
    1. The problem statement, all variables and given/known data
    A wire of material having density of 8.0 g.cm-3 is stretched so that its length is increased by 0.10%. The fundamental frequency of transverse vibrations of a part of the wire 50.0 cm long is then 150 Hz. Calculate:

    (a) the velocity with which a transverse wave is transmitted along the stretched wire,

    (b) the tension per unit area of cross-section of the wire,

    (c) Young’s modulus for the material of the wire.

    2. Relevant equations

    3. The attempt at a solution
    I have solved this--- a) is simple the wave length is 0.5*2 therefore the velocity is 150m/s
    b) it says per unit area of cross section. however i have rho times Area = mu which ends up giving me a Tension by unit area of 1.8*10^8n*m^2 not per if you get what i mean
    c) is simple enough F/A=deltaL/L * Y the Area cancels (suggesting my answer for b is right) and so do the L's leaving a youngs modulus of 1.8*10^9

    can someone do this and see if they agree with me please...
  2. jcsd
  3. May 27, 2010 #2
    Hey Pat,

    I agree with your answers for all of them. Im not sure if you done b the same as me, but i used v = SQRT.(T/[tex]\mu[/tex]). I done these before i even looked at your thread so either we bothed stuffed it up, they seem pretty out ..
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