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Homework Help: Problem with geometry in conservation of energy problem

  1. Dec 20, 2012 #1
    My problem is with where the initial height being R - R cos theta. I don't really get where that came from. any hints on where i could look to find the answer or suggestions on how to start are greatly appreciated.

    nevermind i figured it out

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    Last edited: Dec 20, 2012
  2. jcsd
  3. Dec 20, 2012 #2


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    Hello insomniac1. Welcome to PF!

    In the figure shown in the problem statement, construct a right triangle where the hypotenuse is the cable of length R as drawn in the figure, another side of the triangle runs vertically from the pulley (extend the dotted line shown), and the third side is horizontal from the man to the vertical side of the triangle. Can you use that triangle to help you see where the expression R - Rcosθ comes from?

    (If you want to access symbols like θ, click on the "Go Advanced" button below the reply box.)
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