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Homework Help: Relating friction with acceleration

  1. Mar 2, 2009 #1
    1. The problem statement, all variables and given/known data
    If the coefficient of kinetic friction between tires and dry pavement is 0.80, what is the shortest distance in which you can stop a car by locking the brakes when traveling at 28.7 m/s?


    2. Relevant equations
    The problem doesn't state the mass of the car, so I'm not sure how to exactly relate kinetic friction with the acceleration.


    3. The attempt at a solution
    v^2 = 0 + 2a(x - 0)
    v^2/2a= x

    a?
     
  2. jcsd
  3. Mar 2, 2009 #2

    LowlyPion

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    Homework Helper

    Mass will drop out.

    What is the maximum deceleration the car will tolerate?

    Won't that be when m*a = μ*m*g ?
     
  4. Mar 2, 2009 #3
    OHHHH so it doesn't even depend on mass, so I can plug a = ug, which just gave me the correct answer :)

    Thanks!
     
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