Units in physics mode


For an upcoming class, I am trying to figure out units in the physics engine. Trying to demonstrated two spheres colliding - like in a game of pool. However, I am struggling to understand the values (do they have physical units?) of bounciness and friction needed to get a realistic collision - same mass, one ball stopping the other running with the speed of the other one. Here is my attempt - https://cospac.es/v73w

Any help appreciated.