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Homework Help: Finding height using Conservation of Energy

  1. Oct 5, 2008 #1
    1. The problem statement, all variables and given/known data
    A skier (m=61.00 kg) starts sliding down from the top of a ski jump with negligible friction and takes off horizontally. If h = 6.70 m and D = 9.80 m, find H.

    I already found the velocity as he leaves the cliff to be 29.2 m/s

    Here's a picture of it: http://img264.imageshack.us/my.php?image=prob21agz5.gif

    2. Relevant equations
    E[1] + W[non conservative] = E[2]
    K= .5mv^2
    U= mgh

    3. The attempt at a solution

    w[nc]= 0 (no friction)
    K[1]= 0, U[2] = 0 so K[2] = U[1]

    K[2]= .5*61*29.2^2
    K[2]= 26005.52

    26005.52 = mgH
    26005.52/ (61*9.8) = H
  2. jcsd
  3. Oct 5, 2008 #2


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    Homework Helper

    Can you show how you got this? That's a pretty high speed.
  4. Oct 5, 2008 #3
    You're right, and after reworking I found the speed to be 8.38 m/s which gave me the right answer
  5. Oct 5, 2008 #4
    which I found using V= d* (square root of( g/2h))
  6. Oct 5, 2008 #5


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    Homework Helper

    That looks much better!
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