1. The problem statement, all variables and given/known data What I would like to do is find the minimum velocity needed to launch a projectile from point A to B when B is not at the same height as A. I keep finding myself stuck with two unknowns (initial speed and release angle) and I am not sure how to resolve them. If the problem is simplified and the angle is fixed or the initial speed is fixed then the solution resolves to one variable and is relatively easy to solve. However if release angle or initial speed is not fixed then there is an infinite number of angles and speeds which will take a projectile from A to B. As the release angle approaches 90 degrees the initial speed tends towards infinity as it does if the angle "points" directly at the target. So I assume there is a middle ground where the minimum velocity can be calculated. Any help is much appreciated, many thanks. 2. Relevant equations I'm not sure how to paste equations onto this page but most of the information I have found is on http://en.wikipedia.org/wiki/Range_of_a_projectile and http://en.wikipedia.org/wiki/Projectile_motion. 3. The attempt at a solution If point A and B are flat then the "perfect" angle is 45 degrees and the speed needed to get from A to B is quite easy to work out. However if B is above or below A then I'm not sure how to calculate the "perfect" angle.