Say I have two balls of same radius, in the 2-D Plane. So like a pool (billiard) game. I have the cue ball, moving with the velocity vector V, the magnitude is not important, so we only need an angle to define the velocity, which is theta.
Depending on theta and r, the balls may or may not collide. So let's say we know that they will collide, and we know the initial positions, radii, as well as theta. So how do we calculate the angle of movement of the second ball ?
I hope the picture helps if I failed to define the problem.
Although I stated the problem with theta, I'm also ok with a vector-form solution.