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Homework Help: Displacement given coefficient of friction and velocity

  1. Jun 18, 2010 #1
    1. The problem statement, all variables and given/known data
    A car is traveling at 56.0 km/h on a flat highway. If the coefficient of friction between road and tires on a rainy day is 0.100, what is the minimum distance in which the car will stop?



    2. Relevant equations
    μ=-a/g
    v2=vo2 + 2 a x


    3. The attempt at a solution
    56.0 km/h = 15.6 m/s

    0.100=-a / 9.8 m/s2
    a= 0.98 m/s2

    0=(15.6 m/s)2 + 2 (0.98m/s2) x
    x= 245.3 m
     
  2. jcsd
  3. Jun 18, 2010 #2

    PhanthomJay

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    Your equation is good but check your math(s)...and minus sign
     
  4. Jun 18, 2010 #3
    oh i accidently subtracted instead of divided. oops thanks!
     
  5. Apr 3, 2011 #4
    How do you no the equation:
    the coefficient of friction=-a/g ?
     
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