1. The problem statement, all variables and given/known data At what height h above the ground does the projectile have a speed of 0.5v? 2. Relevant equations K_1 + U_1 = K_2 + U_2 K = 1/2mv^2 U = mgh 3. The attempt at a solution I made the point where the speed is .5v = point 1, and the maximum height = point 2. Point 1: K_1 = 1/2m(v_1x^2 + v_1y^2) U_1 = mgh Point 2: K_2 = 1/2m(v_2x^2 + v_2y^2) U_2 = mg(v^2/2g) = (mv^2)/2 <--maximum height, I got this from the previous part. Then it's just plug and chug into the eqn K_1 + U_1 = K_2 + U_2 but I came out with the wrong answer which is (-v^2/8g). Oh I took out the v_1x^2 and the v_2x^2 because the x component remains constant throughout and I also took v_2y^2 because it's 0 at maximum height. I must have done something wrong somewhere but I have no idea (probably my setup) so pls help?