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Homework Help: Conservation of Momentum problem

  1. Mar 23, 2008 #1
    [SOLVED] Conservation of Momentum problem

    1. The problem statement, all variables and given/known data

    A tennis player receives a shot with the ball (0.0600 kg) traveling horizontally at 54.0 m/s and returns the shot with the ball traveling horizontally at 34.0 m/s in the opposite direction. (Assume the initial direction of the ball is in the -x direction.)

    (a) What is the impulse delivered to the ball by the racquet?

    (b) What work does the racquet do on the ball?

    3. The attempt at a solution
    I got part A by finding the change in initial and final momentum of the ball (5.28).

    I thought I could get part B by: mv = 5.28 so v = 88 m/s; and plug that into .5mv^2 to find the energy. That was wrong though and now I am not sure how to solve it.
  2. jcsd
  3. Mar 23, 2008 #2

    Doc Al

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    Staff: Mentor

    Find the change in kinetic energy.
  4. Mar 23, 2008 #3
    Ok thanks for the help. Makes sense.
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