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Homework Help: Jumping off a snow pile

  1. Dec 19, 2015 #1
    1. The problem statement, all variables and given/known data
    The diagram shows a kid jumping off a snow pile into the grown that is also covered with snow. So the kid is jumping up and then lands on the ground.
    The question is: how tall is the snow pile if the ground is 0 m?
    2. Relevant equations

    S=v0t + (at^2)/2

    3. The attempt at a solution
    I am thinking that the kid is at its highest point when the velocity is zero and t=0.4. It takes 0.4 seconds up and also 0.4 seconds down to the level where the snow pile was at. so the snow piles height is from 0.8 seconds to 1,2 seconds. 1.2-0.8=0.4
    s= -4*0.4 + (9.82 * 0,4^2)/2 = - 0,8144

    What went wrong in my assumptions or solution?

  2. jcsd
  3. Dec 19, 2015 #2


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    Staff: Mentor

    If it's headed downwards, you are denoting this as a negative velocity, so g in your equation will likewise be negative.
  4. Dec 19, 2015 #3


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    Staff: Mentor

    Also, when the velocity is at its most negative point, that's when the kid reaches the top of the layer of snow that's on the ground, not the ground itself. Ponder the finish of the velocity vs time graph.
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