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Homework Help: Kinetic energy

  1. Jan 2, 2008 #1
    okay, i tried searching knietic energy and it wont come up,
    soooo here's a questions:

    a force of 40 N continues to push a 5 kg box and acclerates it a .70 m/s/s what is the coefficient of friction/

    i got the static because it wasn't movingm, but i have no idiea how to get that please help
  2. jcsd
  3. Jan 2, 2008 #2

    Shooting Star

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    First, tell us what was the net force acting on the body.
  4. Jan 2, 2008 #3


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    This problem has nothing to do with kinetic energy! As shooting star said (I seem to spending the day right behind him!), it is entirely a matter of force. What is the net force on the body? Also I have no idea what you mean by "I got the static because it wasn't moving". What wasn't moving? What "static"?
  5. Jan 3, 2008 #4

    Shooting Star

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    Do you by chance mean you "get" the case for static friction? Anyway, reply to our questions if you want to understand the problem.
  6. Jan 3, 2008 #5
    if the acceleration is .7 m/s^2, and the box has a mass of five kilograms, Newton will only take a second to tell you the net force on the box.

    Of course, if there's a difference between the applied force and the net force, there must be another force acting on the box. This is where you'll find your kinetic friction.
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