does anybody know of any good sites that explain the physics and geometry of playing billiards (pool) ?
The problem with this is that the effects of english (spin placed placed on the cue ball when hit) changes the geometry, effecting the cue ball bouncing off a cushion, draw, etc. and just generally make a mess of the geometry.This is probably all stuff you know but the most basic rule is just the geometric principle that the angle of incidence will equal the angle of reflection. So if the ball hits the side of the table at an angle of 25 degrees, it will rebound at that angle. If a ball hits another ball, the angle that it bounces off at will be similar to the ball bouncing off a wall tangential to the surface of the (struck) ball. When you hit the cue ball, the momentum from the stick is transferred to the cue. The cue transfers part of its momentum to whatever it hits. The total momentum is conserved, so that knowing the initial conditions should lead you to predict the outcome with vector analysis.
I don't think the distance that the cue-stick travels is a factor. Perhaps you are only hitting the ball softer, or closer to center when this happens.Originally posted by schwarzchildradius
I've noticed that if I move the stick a shorter distance before it strikes the cue the cue bounces back less after it hits a ball. Lower momentum gives you less friction.