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Homework Help: Rotating rod

  1. Feb 20, 2007 #1
    1. The problem statement, all variables and given/known data
    The rod of length 2a swings and it rotates [itex]\dot{\phi}[/tex]. Find kinetic energy.

    3. The attempt at a solution

    I know how to find kinetic energy if we have rotation just in xy plane, but I'm having a problem to understand how to do it with rotation around y axis.

    If we have rotation in xy plane:

    For rotation around y, I assume that we have translation component in z direction, and rotation component.
    Is this correct? (look at the picture)
    Rotation part of [itex]E_{z}[/itex] bothers me, maybe I have to multiply it by [itex](lsin(\theta))^2[/itex].

    Attached Files:

    • rod.JPG
      File size:
      5.1 KB
    Last edited: Feb 20, 2007
  2. jcsd
  3. Feb 20, 2007 #2
    Is this ok:


    Last edited: Feb 20, 2007
  4. Feb 21, 2007 #3
    I have successfully solved the problem by my self, so no need for an answer.
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