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Homework Help: Simple harmonic motion, finding displacement given time

  1. May 7, 2008 #1
    1. The problem statement, all variables and given/known data

    mass = 1.8kg
    given equation in problem x(t) = (7.40cm)cos[(4.16s^-1)t - 2.42]
    *when i tried solving i converted 7.40cm to 0.074m

    find the position of the mass at t = 1.00s

    2. Relevant equations

    x(t) = (7.40cm)cos[(4.16s^-1)t - 2.42]

    3. The attempt at a solution

    i've been working on this problem for a while, i haven't been able to get the correct answer, even when i made sure to check units and make necessary unit conversions. i made sure my units were in radians (within the cosine) but it keeps yielding the wrong answer, i was able to find velocity and acceleration from the given equation, just not position.

    i thought this problem would be just plug and chug, when i stuck t=1.00s it still hasn't given me the correct answer, i got -0.01 and 0.074, both were incorrect

  2. jcsd
  3. May 7, 2008 #2
    EDIT sorry for double posting - actually was kinda correct the first time, it was just very picky with sig figs, i initially entered -0.01 which was incorrect, the actual answer was -0.0125
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