[SOLVED] Projectile motion 1. The problem statement, all variables and given/known data A ball is thrown with an intial velocity of v0 at an angle theta from the horizontal. Find the flight time of the ball in terms of H and g only. 2. Relevant equations t = (2 v0 sin theta)/g 3. The attempt at a solution Ok. I found theta to be the tan inverse of 4R/H. Thus, the initial velocity is sqrt[Rg/sin(2tan-1(4R/H))] - a little longwinded but accurate. However, my problem arises when I plug these values into the above equation and those really nasty 'R's refuse to go away, and the problem specifically states that g and H should be my only variables. I feel like i must be missing something really obvious, and if so, i apologise in advance, but please help anyway! Thank you!