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Homework Help: Rotation of Rigid Body

  1. Feb 13, 2006 #1
    A metre rule is freely pivoted about its centre. A piece of mud of mass 20g travelling at 5ms-1 strikes and sticks to one end of the rule so that the rule starts to rotate in a horizontal circle. If the moment of Inertia of the rule and the mud about the pivot is 0.02kgm^2, the initial angular velocity of the rule is....(Answer:2.5rads-1)

    I have made assumption that the momentum of the mud is transfer solely to
    the angular momentum. (mv=Iw)
    I got the answer 5 rads-1, obviously wrong. I believe that my assumption is wrong. How should I attempt this question?
  2. jcsd
  3. Feb 13, 2006 #2
    mks units

    hi harmony

    make sure you convert all units to m-> meters, k-> kilograms, and s-> seconds...then you should get the correct answer with your assumption.

    ahhh actually im wrong i was reading your post backwards. i thought 5 rad/s was the correct answer...gonna have to think about this for a little while

    Last edited: Feb 13, 2006
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