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Homework Help: Centripetal acceleration automobile problem

  1. Oct 27, 2008 #1
    1. The problem statement, all variables and given/known data

    6. A car of mass 1750 kg rounds a circular turn of radius of 21 m. The road is flat and the coefficient of kinetic friction between the tires and the road is 0.3, while the coefficient of static friction is 0.76. How fast can the car go without skidding?

    2. Relevant equations

    Mu(static)mg = mv^2/r

    3. The attempt at a solution
    I understand how to do the problem, I just don't understand why the coefficient of static friction would be used and not the coefficient of kinetic friction since the car is moving and not stationary(static friction)
  2. jcsd
  3. Oct 27, 2008 #2
    The friction force is not the one that opposes the forward motion but rather the force towards the center that provides the centripetal acceleration (thus, stops the motion of the car from going outward).
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