Solving Motion Equations for 2D Elastic Collisions

[cghost]

Hi, I'm trying to make a 2d simulation of elastic colliding balls. I have a hard time deriving the motion equations after collision. For each ball i know the speed, the mass and the angle of movement. Can anyone point me in the right direction to find the general equations for this ? I need the new speed after collision and the new angles which the balls will use as direction. I tried some energy and impulse conservation but i didn't came up with something concrete.
Btw: i don't have friction, rotation or things like this. everything is ideal.

 

[mathman]

Given conservation of energy and momentum, you will have one free parameter, namely the angle after collision.