Finding an angle of trajectory from a tangential launch.

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1. Oct 24, 2014

Jae

1. The problem statement, all variables and given/known data

2. Relevant equations
1/2mv^2, mgh, and basic kinematics equations

3. The attempt at a solution
I set the height = 0 at moment before the launch.

To get the velocity, I used:
energy before the ball starts accelerating (PE) = energy right before the ball leaves the ark (KE)

I'm stuck on Part B, because I'm having trouble getting the angle of the launch.
I set the x axis as the ground.