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Homework Help: Angular velocity of sphere and two points

  1. Apr 5, 2010 #1
    1. The problem statement, all variables and given/known data
    A uniform sphere of mass m and radius R rotates around the vertical axis with angular speed [tex]\omega[/tex]. Two particles of mass m/2 are brought close to the sphere at diametrically opposite points, at an angle [tex]\Theta[/tex] from the vertical. The masses, which are initially essentially at rest, abruptly stick to the sphere. What angle does the resulting [tex]\vec{\omega}[/tex], make with the vertical?

    2. Relevant equations
    so the moment of inertia of the sphere by itself is [tex]I=\frac{2}{5}mR^{2}[/tex]

    3. The attempt at a solution
    I don't really know how to start this question off, or what method I would use. There is a changing moment of inertia, so would I use conservation of angular momentum to find the resulting angular velocity?
  2. jcsd
  3. Apr 5, 2010 #2
    Yes, that's exactly right. Why not try and solve it and show us if you get stuck at any point along the way?

    As a general note, we won't do your homework for you here, you should show your own attempt at the solution in order for us to help you the best we can.
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