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Homework Help: Uniform circular motion of a rolling object

  1. Jun 30, 2004 #1
    A soccer ball of diameter 33cm rolls without slipping at a linear speed of 2.4m/s. Through how many revolutions has the soccer ball turned as it moves a linear distance of 18m?

    How do I just find the revolutions? I know how to use the equation to find rev/s, but how do I just get revolutions?

    Thank you.
  2. jcsd
  3. Jun 30, 2004 #2
    Find out how long it takes for the ball to do a full revolution. Then find out how long it takes for the ball to move 18 metres. Divide the latter by the former and you should get your answer.
  4. Jun 30, 2004 #3


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    Homework Helper

    hint: there is superfluous information in the problem.
  5. Jul 1, 2004 #4
    I'm using the equation N=X/2pi*r. When I do this, I'm getting 8.68 revolutions, but it's wrong. Is there another equation I should be using?
  6. Jul 1, 2004 #5
    Nevermind. I know what I did wrong!!
  7. Jul 1, 2004 #6

    Doc Al

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    Staff: Mentor

    Your equation is correct. Be sure you are using the correct value for the ball's radius.
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