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Homework Help: Period of a physical pendulum

  1. Nov 2, 2008 #1
    1. The problem statement, all variables and given/known data

    A physical pendulum is constructed using a 4.4 kg object having a moment of inertia of 33.9 kg-m2 about its center of mass. The rotation (suspension) point is 276.69 cm from the center of mass. What is the period of this physical pendulum?

    2. Relevant equations

    T = 2pi sq rt (I/mgh)

    3. The attempt at a solution

    Every attempt at this problem yields T = 3.35s. I did a little research to make sure I was using the correct equation, but I didn't find anything to contradict what I'm using. Inertia is kg-m^2; m=4.4kg, g=9.81m/s^2, and h=2.7669m. Any help is appreciated.
  2. jcsd
  3. Nov 2, 2008 #2

    Doc Al

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    Staff: Mentor

    Note that I must be about the suspension point, not the center of mass.
  4. Nov 3, 2008 #3
    That's it! I worked out the problem using I about the suspension point and it's correct. Thank you for the insight.
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