1. The problem statement, all variables and given/known data I completely understand the mathematics behind finding the range of a projectile flying over flat ground. But I cannot find a reliable formula for the projectiles range if it is flying over non-flat ground. Wikipedia had a formula but I did not understand how it could be correct. If someone could either explain the wikipedia formula or tell me the real formula and explain why it works, that would be great as I am giving a talk to some classmates on ballistics soon and must be able to understand and explain the formula. 2. Relevant equations When finding the range of a projectile flying over flat ground, the formula for (v2/g)*sin2A where g is gravitational acceleration on earth and A is the angle at which the projectile is fired. 3. The attempt at a solution wikipedia formula? r= (VcosA/g)*(VsinA+sqrroot((VsinA)2+2gy)) V=initial velocity A=angle at which projectile was launched g=gravitational acceleration on earth y=original height of projectile Thanks!