I have a formula at home that I tried but its not working to well so no use in posting it here. Anyway the idea is I have a 2d space and I hit an object. I have access to this objects position in space and velocity, also the gravity that acts upon this object. Time should not be a factor as I recalculate this every frame (its for a game). I am looking for the x position where it will land, while the y = 0; If need be, I will post my formula from home later but again it gives me very inaccurate answers.