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Homework Help: Center of mass of rod

  1. Feb 7, 2007 #1
    1. The problem statement, all variables and given/known data
    If you have a rod that is pivoted at one end with a mass of 4 kg and a length of 24 m and the other end has a sphere attached to it that is 4 kg and has a radius of 1.5 m, what is the center of mass?

    2. Relevant equations
    MXcm= m1x1 + m2x2

    3. The attempt at a solution
    I think that the center of mass should be where the sphere attaches to the rod, but I feel like that isn't right.
    Last edited: Feb 7, 2007
  2. jcsd
  3. Feb 7, 2007 #2
    The centre of mass will be the middle of the total distance where the total torque is in equilibrium.

    That being said, Once you figure out the torque of one end (going clockwise), you can equate it to torque at the other end (going anticlockwise, so the rod and sphere is static) and the distance can be evaluated, which will be the distance from the end to the middle.

    A diagram really helps.
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