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Homework Help: Angular Acceleration of a rotating wheel

  1. Oct 27, 2006 #1
    A rotating wheel requires 2.98 s to rotate through 37.0 revolutions. Its angular speed at the end of the 2.98 s interval is 98.8 rad/s. What is the constant angular acceleration of the wheel?

    First I tried acceleration = (98.8rad/s - 0 rad/s) / 2.98 s - 0s = 33.15, which was incorrect.

    Then I tried acceleration = (98.8rad/sec)^2 - (0 rad/sec)^2 = 2 * acceleration * 74pi and solving for acceleration i got 20.99 but thats incorrect too. I got 74 pi by converting 37 rev.

    Any clue as to what I'm doing wrong?
     
  2. jcsd
  3. Oct 27, 2006 #2

    OlderDan

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    If all the information given in the problem is correct, the wheel is not starting from rest.
     
  4. Oct 27, 2006 #3
    Huh, I guess I never considered that. That's frustrating :\ Thanks for your help though :)
     
  5. Nov 2, 2006 #4
    never mind, i got it :)
     
    Last edited: Nov 2, 2006
  6. Nov 2, 2006 #5

    OlderDan

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    I thought you had it when you posted your previous reply. Sorry if you were expecting something more.

     
  7. Nov 2, 2006 #6
    Oh no, I stopped looking at the problem for a while. But I decided to come back to it, and I had posted another question, but in the meantime I figured out the answer so I edited my post to the one you quoted. No worries :)
     
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