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Homework Help: How high can he jump?

  1. Nov 16, 2008 #1
    1. The problem statement, all variables and given/known data

    A 73 kg high jumper leaves the ground with a vertical velocity of 7.6 m/s.
    How high can he jump? The acceleration of gravity is 9.8 m/s^2.


    2. Relevant equations

    mgh1 + 1/2mv1^2 = mgh2 + 1/2mv2^2

    3. The attempt at a solution

    0 + 1/2(7.6)^2 = 9.8(h2) + 1/2(v2)^2

    How can you solve this when you two unknowns?
    Does v1 = 7.6 also apply to v2?
    Am I using the right equation?
     
  2. jcsd
  3. Nov 16, 2008 #2
    Correct equation...Concept:when the jumper has jumped his highest at that point "instantaneously" his velocity becomes zero..So set v2=0 and head on with the math.
     
  4. Nov 16, 2008 #3
    Alright thank you, that helps a ton.
     
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