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Homework Help: What is the circumference of the track?

  1. Dec 21, 2009 #1
    A student runs at a speed of 8.50 m/s on a circular track. If she accelerates a 1.03 m/s2, what is the circumference of the track?


    8.5m/s*1.03m/s?
     
  2. jcsd
  3. Dec 21, 2009 #2

    AEM

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    Re: Circumfrerence

    The wording of the problem implies that the velocity of the girl is a constant and therefore the acceleration referred to is centripetal acceleration. There is a nice equation that expresses the relationship between radial acceleration (centripetal acceleration), velocity and the radius for motion in a circle. So all you need to do is use that to find the radius and use [itex] C = 2 \pi r [/itex] to compute the radius.
     
    Last edited: Dec 21, 2009
  4. Dec 21, 2009 #3
    Re: Circumfrerence

    Thanks! :) so it would be:

    2(3.142)14?
     
  5. Dec 21, 2009 #4

    AEM

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    Re: Circumfrerence

    No, I don't get that at all. The equation I have in mind is [itex] a = \frac{v^2}{r} [/itex]. That will allow you to calculate r.
     
    Last edited: Dec 21, 2009
  6. Dec 21, 2009 #5

    AEM

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    Re: Circumfrerence

    That's a v squared. It doesn't come out on my computer screen.
     
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