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Homework Help: Max speed of wave on a string from elastic limit given density

  1. Nov 18, 2006 #1
    How do I set this up? "The elastic limit of a piece of steel wire is 2.7 X 10^9 Pa. What is the maximum speed at which transverse wave pulses can propagate along this wire before this stress is exceeded? (The density of steel is 7.86 X 10^3 kg/m^3)

    I know [tex]v = \sqrt{\frac{T}{\mu}}[/tex] so I guess I'd solve for T? And how do I pull the force from the elastic limit without the area?

    thanx!
     
  2. jcsd
  3. Nov 18, 2006 #2

    nrqed

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    Hi.

    Notice that [itex] \rho = { mass \over length \times area} [/itex] and [itex] \mu = {mass \over length} [/itex] so that [itex] \rho = {\mu \over area} [/itex] where, by "area" I mean the cross sectional area.

    Also, Pressure = Force over area, so [itex] P_{max} = {T_{max} \over area} [/itex]. With this you should be able to rewrite the speed in terms of the pressure and the volume mass density [itex] \rho[/itex].

    I hope this helps

    Patrick
     
  4. Nov 18, 2006 #3
    yes it helped! i hope i remember it! thanks!
     
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