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Homework Help: Please help asap classical mech( harmonic oscillator)

  1. Oct 7, 2005 #1
    Please help
    1) The mechanism which powers the clock (using a harmonic oscillator to keep time with friction) Since the clock has friction the oscillation amplitude decreases in time. If the oscillation amp is unity at t=0 what will the amp be after 10 sec?

    I believe we need to use the equation w=sq rt(k/m-(c/2m)^2)
    But i'm not exactly sure what is the correct way to arrpoach this problem, Any hint would be appreciated!! thanks!
  2. jcsd
  3. Oct 7, 2005 #2


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    Homework Helper

    They're not asking (at this point) for the new *angular frequency*,
    they're asking for the *envelope* of the decaying cosine curve.
    x(t) will be A_o exp(-t/tau) cos(wt + phi) ; the question is about
    the exp(-t/tau) portion. You need to know how strong friction is,
    or how much frictional work is done in a cycle with total Energy E.
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