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Question with solution, confused on how time was found.

  1. Jul 7, 2017 #1
    1. The problem statement, all variables and given/known data
    A skier (m=59.0 kg) starts sliding down from the top of a ski jump with negligible friction and takes off horizontally. If h = 6.60 m and D = 10.6 m, find H.

    2. Relevant equations


    3. The attempt at a solution

    The solution was provided, this is a sample problem. I'm just very confused in how t was found to be sqrt(2h/g)

    http://imgur.com/a/UuRNp

    [​IMG]
     
  2. jcsd
  3. Jul 7, 2017 #2
    I assume you are referring to the fourth line where time was substituted out using the equation
    $$t=\sqrt{\frac{2h}{g}}$$.
    This is simply the time taken for an object to fall a vertical distance ##h## and comes from re-arranging the one-dimensional motion equation
    $$x=\frac{1}{2}at^{2}$$
    and using ##h## for vertical distance and ##g## for acceleration.
     
  4. Jul 7, 2017 #3

    haruspex

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    How are D, h and H defined in the question? The link to the solution works, but it looks like there is also a broken link, perhaps to the original question, or a diagram of it?
     
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