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Homework Help: Find the distance the car travels before it stops

  1. Nov 19, 2006 #1
    A car wants to stop. The coefficient of friction is 0.3 and the mass of the car is 2000 kg. The car is traveling at 50 km/hr. Find the distance the car travels before it stops.

    I know that the force of friction= the coefficient of friction x the normal force. I also know that I need to change 50 km/hr to m/s. I can't quite figure out how to find the normal force on this one(would i subtract friction from it or add it or what), and I don't see how I could find the distance it would take to stop because I do not know the time or the acceleration. Please help!
     
  2. jcsd
  3. Nov 19, 2006 #2

    radou

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    Homework Helper

    The work of the frictional force must equal the change of kinetic energy of the car, start with that.
     
  4. Nov 19, 2006 #3
    so does that mean that the force of friction equals the change in velocity?
     
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