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Homework Help: Waves frequency

  1. Mar 27, 2010 #1
    1. The problem statement, all variables and given/known data

    One end of a string of mass 1.45 g and length 50.0 cm is attached to a frequency generator and the other end to a weight holder which hangs over a fixed pulley . The part of the string between the generator and the pulley is horizontal . THe string is set to vibrate . Several weights are added until a fundamental frequency of 120 Hz is achieved . Calculate the tension in the string when the fundamental frequency is achieved .

    2. Relevant equations



    3. The attempt at a solution

    f=v/2L

    120=v/(2 x0.05)

    v=120 m/s

    not really sure whether this is even an attempt . I do not know how to link the v i got here to tension in the string .
     
  2. jcsd
  3. Mar 27, 2010 #2

    rl.bhat

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    Homework Helper

    Try to find the relation between tension, mass per unit length and the velocity of the wave in the stretched string.
     
  4. Mar 27, 2010 #3
    i am not sure how to relate them since the unit of tension is kgm/s^2 , mass per unit length is kg/m and velocity , m/s

    how can i combine m/s and kg/m to get kgm/s^2 ?
     
  5. Mar 27, 2010 #4

    rl.bhat

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    Homework Helper

    What is the value of
    [tex]\sqrt{\frac{kgm/s^2}{kg/m} = ?}[/tex]
     
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