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Homework Help: Rigid body rotation. Need explanation

  1. Oct 6, 2012 #1
    1. The problem statement, all variables and given/known data

    https://dl.dropbox.com/u/66988308/Capture.JPG [Broken]

    2. Relevant equations
    V=rW


    3. The attempt at a solution
    I tried to plug in the forumla , and algebras but I keep getting rc/rf as answer instead of rf/rc as the book says.
    Work:
    Vf=(rf)W
    W=Vf/rf
    W=Vc/rc

    Vc/rc = Vf/rf
    (Vc)(rf) = (Vf) (rc)
    (Vc)(rf) / (Vf) (rc)= 1
    Im not sure if this is the right track.
    Thanks for any advice.
     
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Oct 6, 2012 #2
    Please show your working.
     
  4. Oct 6, 2012 #3

    lewando

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    Gold Member

    The book is correct.
     
  5. Oct 6, 2012 #4
    My work is shown in first post now.
     
  6. Oct 6, 2012 #5

    lewando

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    Gold Member

    "W" (ω), angular velocity, is not the same in each case.
     
  7. Oct 6, 2012 #6
    Do you know what angular momentum is?
     
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