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Forces on an Inclined Plane Question

  1. Sep 12, 2006 #1
    Hi I have a problem that reads: A car drives downhill on a road that is inclined 20 degrees to the horizontal. At a speed on 30 m/s the driver suddenly brakes until the car stops (coefficent of kinetic friction = .8, coefficent of static friction = .9).
    A. When all of the wheels are locked, how far will the car skid over the road until it stops?
    B. What is the steepest slope of a road on which a car can rest (with locked wheels) w/out slipping? Find the equation and maximum angle of the incline.

    I began the problem and am not quite sure what to do. Once I drew the free body diagram I tried multiplying the 30 m/s by the .8 kinetic friction to get 24N of friction while the car still moves. It doesnt tell me how to find distance traveled though and there is no mass of the car given. I don't really know what to do with the coefficents and haven't used them yet in class. Also, for part B do we solve with an inverse cos or sin? Thanks.
    Last edited: Sep 12, 2006
  2. jcsd
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