# Need a trajectory equation

s w
I'm in the process of created a computer game and I want to introduce a mortar into the game. What I want to do is given the initial position, target position, and target height, calculate the force vector that is needed to launch the mortar so it hits the target height and target distance. The reason I put a target height in there is so the mortar is doing an appropriate parabolic arc. I dont want it to just do a slight arc and hit the target, I want it to go relatively high but still remain inside the bounds of the level.

So to summarize. I know the initial position, target position, target height, mass of the object, and gravity (assume no drag) and I want to know the force vector needed. It also must be said that the initial and target positions lie in all 3 planes. So I'd really like to be able to hit a target that is higher or lower than the initial position if possible. As for the target height, that is the height above the initial position.

## Answers and Replies

sentinel
it depends if you have the resisting force of air and in what magnitude?F=kmv or F=kmv.v or ...... and this depends on your estimated speed, without resistance: X=V*COSa*t,Y=(V*SINa*t)-((1/2)*g*t.t)

s w
Quoted from above.
(assume no drag)

sentinel
i dont study physics in english so i am not familiar with some words but anyway just use the equations i mentioned in three dimension(x,y,z) and simply use F=ma thing on them, plus ,if you want to calculate the resistance first check your estimated speed with some table to see if the resistance is kmv or kmv.v and also you can estimate it by using the taylors formula or somethinh(f(X)=a1+a2x+a3xx+a4xxx+.....) then cut off from xx.