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Homework Help: Phase angle question (SHM)

  1. Nov 14, 2006 #1
    question 1)

    If a simple harmonic oscillation is described by the function

    x = A sin (wt + phi)

    would phi be the opposite of what it would be for a SHM described by the function

    x = A cos (wt + phi)

    I.e if the graph for for x = A sin (wt + phi) , when t = 0, x = +A. would phi be equal to pi instead of 0( as it would for x = A cos (wt + phi)

    question 2)

    For a mass m attached to a spring that undergoes simple harmonic motion, The spring
    constant is k.

    Does the elastic potential energy ever equal the kinetic energy at one point x?

    this isnt a hw question, just my curiosity..

    Last edited: Nov 14, 2006
  2. jcsd
  3. Nov 14, 2006 #2
    1. If [tex] x = A\sin(\omega t + \phi) [/tex] and [tex] x = +A [/tex] at [tex] t = 0 [/tex], then [tex] A = A\sin(\phi) [/tex].

    So [tex] \phi = \frac{\pi}{2} [/tex]
  4. Nov 14, 2006 #3
    thanks alot!
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