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Homework Help: Finding initial velocity and theta, given range and height

  1. Sep 13, 2008 #1
    1. The problem statement, all variables and given/known data

    A stone is thrown down a slope. I am given the Range of the slope and the max height from spot thrown.
    R= 50m
    h= 12m

    2. Relevant equations

    I need to determine the magnitude of Vo and inital theta.

    3. The attempt at a solution

    First I need to find V_o:
    I feel that the only relevant portion to find the initial velocity is from the spot thrown to the max height where V_yo is 0. I broke up the components of velocity so that:

    However, I'm lost after this because I don't know t. My first idea was to find t, but I was having problems finding an equation that doesn't use v, theta, in a time equation.
    My second idea was to find an equation that avoids time such as v_y^2=V_yo^2-g(y-yo).

    I haven't attempted the initial theta part yet.
  2. jcsd
  3. Sep 14, 2008 #2
    Reading through this post, this morning, I realized I forgot to add that the slope has a rise of 30m and a run of 40m. I don't feel that would help with find V_o though. :/
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