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Homework Help: Waves in wires/strings

  1. Aug 3, 2008 #1
    1. The problem statement, all variables and given/known data
    I have been writing up a Physics Experiment with working out the speed of waves in a wire.
    The wire is stretched across two points which send vibrational pulses down the wire. I am stuck with working out the Mass of the wire throw theoretical methods? hope anyone can help.....

    2. Relevant equations
    Wave speed=122ms-1
    Mass of length=?

    Wave speed=(tension T/mass per unit length)1/2

    3. The attempt at a solution
    My answer mass=.21029gm^2, just not sure if this is right, it sounds to light for the length of the wire. hope anyone has any ideas ;)
  2. jcsd
  3. Aug 3, 2008 #2


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    Staff Emeritus
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    Gold Member

    You need to pay better attention to your units. How could the wire have a mass in g 2? is not mass just grams? Also in your post you give the Tension in N 1/2 ??? What is that?

    All you need do is solve your given expression for mass per unit length. This quantity will have units of [itex] \frac {kg} m [/itex]. Then multiply by your length to get a result in kg.
  4. Aug 3, 2008 #3
    right I see what you mean, sorry about N 1/2 i meant the tension is in newtons to the power of a half, but i understand why i went wrong, thanks for the help. Cheers Intergral
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