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Rolling Spool

  1. Jun 16, 2012 #1
    I have a question about a spinning spool, there is a spool spinning and is the sistance travelled by the circumference the same as the center of the circle? You can refer to the diagram attached for a question I had trouble with from a physics olympiad. The answer
    was (B).
    Thanks in advance!!
     

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  2. jcsd
  3. Jun 16, 2012 #2

    Doc Al

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    I assume you are asking: When the rolling spool makes one complete turn, has it traveled a distance equal to the circumference?

    What do you think? (Cut out a circle and try it!)
     
  4. Jun 16, 2012 #3

    A.T.

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    The top of the spool moves twice as fast as the center. But what happens when you pull it under the center?

    https://www.youtube.com/watch?v=dvyii6QBLtw
     
  5. Jun 16, 2012 #4

    haruspex

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    I think the easiest way to figure it out is to consider a very small movement. The spool as a whole rotates about its point of contact with the ground.
     
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