  We study the collision dynamics of a spinning cue ball approaching a static
object ball with equal mass on a plane, common in billiards. While typical
collisions in billiards are nearly perfectly elastic, with a restitution
coefficient close to 1 and low friction, we explore three deviations from ideal
elastic collisions: The non-elastic nature, the friction effects between the
balls during collision, the friction between the ball and the table. We
describe the detailed collision outcomes, emphasizing the importance of
considering frictions. We reveal that friction, both between the balls and with
the table, significantly influences the post-collision motions, deviating from
the expectations of a purely elastic collision. The insights gained contribute
to a better understanding of ball dynamics, impacting strategies and gameplay
in billiards.
