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Homework Help: Energy methods problem

  1. Feb 17, 2007 #1
    1. The problem statement, all variables and given/known data

    How much work must be done by frictional forces in slowing a 1000kg car from 24.9 n/s to rest

    2. Relevant equations

    3. The attempt at a solution

    I just never fully understood how slowing down worked. I just need a nudge in the right direction not you guys doing the work for me. I don't think I'm supposed to do a force analysis, but then again I don't know how to do the problem.
  2. jcsd
  3. Feb 17, 2007 #2


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    If you are familiar with energy methods, you should start there. Look at the car's mechanical energy at the beginning and at the end of its motion. Assume level ground.
  4. Feb 17, 2007 #3
    You will set the frictional force equal to the force required to slow the car from 24.9 m/s to 0 m/s.
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