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Homework Help: Angular velocity + Friction

  1. Oct 21, 2007 #1
    1. The problem statement, all variables and given/known data

    Jim rides his skateboard down a ramp that is in the shape of a quarter circle with a radius of 6.50 m. At the bottom of the ramp, Jim is moving at 2.82 m/s. Jim and his skateboard have a mass of 67.0 kg. How much work is done by friction as the skateboard goes down the ramp?
    ______J



    2. Relevant equations

    angular velocity? + frictional force equation?

    3. The attempt at a solution

    How is the frictional force determined from this with out the kinetic friction coefficient?
     
  2. jcsd
  3. Oct 21, 2007 #2

    G01

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    Homework Helper
    Gold Member

    In this case you do not actually need the force of friction to find the work done by it.

    HINT: Think in terms of conservation of energy. What can this principle tell you about this problem?
     
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