Alrighty, i'm working on a three dimensional physics simulator that does every operation in spherical coordinates and vectors, and i'm stuck on figuring out elastic collisions. are elastic collisions essentially trading momentum between the two colliding bodies? i'm assuming not, but i can't seem to find a simple equation to figure it out. by simple, i mean that just uses vectors. right now i've got two momentum vectors, and each vector can be added to (translate both vectors to Cartesian and add and convert back), subtraction (addition with the other vector being negated), multiplication and division (only via scalars) and i am able to convert back and forth between Cartesian. using that is there any simpler way of doing elastic collisions?