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Conservation of energy?

  1. Mar 29, 2005 #1
    Conservation of energy??

    This is suposed to be a problem concerning Conservation of Mecanical Energy however when i plug in the equation it does not work out.

    A pole vaulter running at 10 m/s vaults over the bar. Her speed when she is above the bar is 1 m/s.
    Neglecting air resistence and energy lost in the pole, what is her height when she clears the bar?
     
  2. jcsd
  3. Mar 29, 2005 #2

    SpaceTiger

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    What are you getting and why do you think it doesn't work out?
     
  4. Mar 29, 2005 #3
    I am useing the equation ½mvi² + mgyi = ½mvf² + mgyf, however i am getting yf as 9 meters and that is too much for a pole vaulter so i am not sure what i am doin wrong
     
  5. Mar 29, 2005 #4

    SpaceTiger

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    Your equation looks right. What did you use for vi, yi, vf, and yf? I'm getting about 5 m.
     
  6. Mar 29, 2005 #5

    dextercioby

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    Please,DO NOT DOUBLE POST!!!The problem is really simple,as it doesn't mention about the pole's bending and the elastic energy which would convert in KE for the jumper.

    Daniel.
     
  7. Mar 29, 2005 #6
    Thanks, when i re-did the equation i came out with about 5 also, so guess i was just typing it in wrong.
     
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