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Projectile with different landing height

  1. Sep 2, 2011 #1
    1. The problem statement, all variables and given/known data

    A handball is projected at an angle of 30 degrees with the horizontal from a 20 meter tower with an initial vertical velocity of 10 ms and an initial horizontal velocity of 20 ms. Find the total time of flight.

    2. Relevant equations

    3. The attempt at a solution

    I know that 0=Vi + at will give me time up X2 will give total time for a projectile with same landing height, but what do I need to use if it has a different landing height?
  2. jcsd
  3. Sep 2, 2011 #2
    IIRC that's a lot more info than you need, you only need a function to describe the position of y at any given t, and solve for 0. Since they didn't give you a vector, but an explicit description of vertical velocity, this shouldn't be hard.

    If your position is initially 20m, then

    y = 20 +...

    Your velocity is 10 m/s

    y = 20 + 10t

    Minus acceleration due to gravity..

    y = 20 + 10t - 4.9t^2

    Should describe your projectile at any t.
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