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Homework Help: Angular velocity

  1. Mar 12, 2006 #1
    A merry-go-round is accelerated from rest by a child at a steady acceleration of 0.2 rad.s-2.

    1)How long does it take for the merry go round to reach an angular velocity of 1.4 rad.s-1?
    2)How many revolutions does the merry go round (and the child) make in this time?

    I belive I worked out the first one, where a=w/t. so t=w/a (t=1.4/0.2). Am I correct?.

    However I can't understand the second part..is there an equation to find the number of revs?
  2. jcsd
  3. Mar 12, 2006 #2
    The first question, I think you're right.
    For the second one, find the angle [itex]\theta=\frac{1}{2}at^2[/itex]
    The revolutions are [itex]N=\frac{\theta}{2\pi}[/itex]
  4. Mar 12, 2006 #3
    is it ok to use w=[itex]\theta/t to find the angle?
  5. Mar 12, 2006 #4


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    No because this will only give you an average angular frequencey. As there is acceleration you need to use the equations phuncv87 posted.
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