What is the height of a pole vaulter when she clears the bar?

AI Thread Summary
The discussion centers on calculating the height of a pole vaulter using the conservation of mechanical energy. A pole vaulter with an initial speed of 10 m/s and a final speed of 1 m/s is analyzed, but initial calculations yielded an unrealistic height of 9 meters. After clarification, the correct height when she clears the bar is determined to be approximately 5 meters. The conversation highlights the importance of considering all forms of energy, including the elastic energy from the bending pole. Ultimately, accurate input values in the energy equation lead to the correct height calculation.
budugly77
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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?
 
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budugly77 said:
This is suposed to be a problem concerning Conservation of Mecanical Energy however when i plug in the equation it does not work out.

What are you getting and why do you think it doesn't work out?
 
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 doing wrong
 
budugly77 said:
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 doing wrong

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