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Homework Help: Momentum Question

  1. Dec 8, 2005 #1
    This seems like an easy question.
    A 0.145 kg baseball pitched at 39.0 m/s is hit on a horizontal line drive straight back toward the pitcher at 52.0 m/s. If the contact time between the bat and ball is 0.001 seconds, calculate the average force between the ball and bat during contact.

    I used Average Force= change in momentum divided by change in time.
    I figured the change in momentum to be 1.89 kg*m/s and change in time to be .001 seconds. Dividing, I got 1,890 N. The answer given by the textbook is 13,200 N.
     
  2. jcsd
  3. Dec 8, 2005 #2

    Tide

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    HINT: The change in velocity is 91 m/s.
     
  4. Dec 8, 2005 #3
    you need to use the change in velocity. make sure to take the directions into account.

    edit:

    tide beat me to it! =p
     
  5. Dec 8, 2005 #4

    Tide

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    Gotta be quick, Andrew! ;)
     
  6. Dec 9, 2005 #5
    That's right, i forgot velocity was changing directions. Thank you.
     
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