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Homework Help: Soccer - What was the impulse on the soccer ball

  1. Feb 28, 2009 #1
    1. The problem statement, all variables and given/known data
    A 0.40 kg soccer ball approaches a player
    horizontally with a velocity of 18 m/s to the
    north. The player strikes the ball and causes
    it to move in the opposite direction with a
    velocity of 24 m/s.
    What impulse was delivered to the ball by
    the player? Answer in units of kg · m/s.

    2. Relevant equations

    3. The attempt at a solution
    i did (.4kg)(24m/s)-(.4kg)(18m/s) and i got it wrong so if u can please help
  2. jcsd
  3. Feb 28, 2009 #2


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    Homework Helper

    Re: Momentum

    The key here is direction.

    If it comes in at 18m/s and reverses then it returns at -24m/s.

    -24 - 18 = -42
  4. Feb 28, 2009 #3
    Re: Momentum

    The key to this is directions. Choose one and then all velocities are either positive or negative relative to that. Does that help?

    The Bob

    P.S. It's not my night; second after post, apologies once again.
    Last edited: Feb 28, 2009
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