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Homework Help: Physics Help please?

  1. Jun 12, 2010 #1
    With brakes fully applied, a 1240 kg car deccelerates from a speed of 86.0 km/hr. What is the work done by the braking force in bringing the car to a stop?

    What is the change in the kinetic energy of the car?

    I keep trying and it saying my answers are wrong can anyone help?
  2. jcsd
  3. Jun 12, 2010 #2


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    You need to show your work so we can see what mistake you're making.
  4. Jun 12, 2010 #3
    It's possible to solve the question using the Work-Energy theorem. You've pretty much solved it in your post without noticing.

    You aren't asked for the force or the distance, just the work done in bringing the car to a halt, and that's straightforward.
    Last edited by a moderator: Jun 12, 2010
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