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Homework Help: Issues with motion and force

  1. Sep 20, 2004 #1
    My problem invloves a car with a mass of 1520kg. It's traveling with a speed of 15.0 m/s. I'm asked to find the magnitude of the horizontal net force that is require to bring the car to a halt at 57.5m.

    My reasoning begins, in that I think I should be finding the acceleration and once I've found the acceleration I can find the total force. But, this is producing a rather large number for me that is negative.

    To find the acceleration I used the equation: a = V^2 - Vo^2 / 2x

    Using that equation my answer was -1.96

    I then plugged that into the equation for net force which was: net force = m(a)

    Plugging in the variables I know in that got me the answer -2973.9 But I can't imagine that this is correct.

    Any help would be appreciated.
  2. jcsd
  3. Sep 20, 2004 #2
    Again, nevermind. What I did was correct however, I should have been leaving out the negative sign. Sorry about this.
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