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Homework Help: So lost help

  1. Oct 8, 2007 #1
    so lost!!! help!!

    1. The problem statement, all variables and given/known data

    The brakes of an 800-kg car exert a force of 4.4kN. (a) how long will the brake take to slow the car to a stop from an initial speed of 34m/s

    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Oct 8, 2007 #2

    Hootenanny

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    Hi there lindzpooh and welcome to the forums,

    Do you know a (quite famous) equation that links force, mass and acceleration?
     
  4. Oct 8, 2007 #3
    i know mass is E0=Mc2
    acceleration= change in speed/time interval
     
  5. Oct 8, 2007 #4

    Hootenanny

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    Yes, your second one will be useful, but you need another one as well, Newton thought of it I believe...
     
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