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Momentum and Impulse

  1. Dec 9, 2011 #1
    1. The problem statement, all variables and given/known data

    18. A 75 kg swimmer dives horizontally off a 300 kg raft. If the speed of the raft immediately after the swimmer dives off is 1.0 m/s, at what speed did the diver leave the raft?

    A. 2 m/s B. 4 m/s C. 6 m/s D. 8 m/s E. 10 m/s

    2. Relevant equations


    3. The attempt at a solution
    I can't figure out how to use the equation to solve the problem. The only answer that I could find was 4 m/s and I did that by taking 300/75. Can somebody work it out step-by-step for me please?
  2. jcsd
  3. Dec 9, 2011 #2
    If swimmer and raft are initially at rest, what is the initial momentum of (swimmer + raft)?
  4. Dec 9, 2011 #3
    Conservation of momentum in the x direction may help you. M1v1 + m2v2 = m1v1' + m2v2'

    The ' symbol means prime. The equation represents momentum of two objects before the collision is the same as the momentum of two objects after
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