Collision of two spinning billiard balls and the role of table

Abstract

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.