1. The problem statement, all variables and given/known data At 0.5 of its maximum height, the speed of a projectile is 0.75 of its initial speed. What was its launch angle? 2. Relevant equations Not sure here, but: v^2 - vo^2 = 2as [maximum height] Ay = Asin(theta) [y-component] 3. The attempt at a solution I didn't get very far, but: vo = vo v = 0.75 vo 0.75vo^2 - vo^2 = (2)(-9.8)s -0.25vo^2 = -19.6s vo^2 = 784s I'm stuck from here on, should I try to find the y-component for this? [Also I'm an almost total beginner at Physics, excuse me if I'm totally wrong]. Any help would be greatly appreciated. Thanks everyone!