Two and a quarter inches is typical of the balls at the American "pool" halls where I go to play eight ball or nine ball. However, interestingly enough, there are quite a few ball size standards for the various billiard games around the world. Read the Wikipedia entry on the Billiard ball to learn more:
http://en.wikipedia.org/wiki/Billiard_ball
The Billiard Ball was created in 1967.
work.
Friction between the ball and cloth.
Friction between the ball and cloth.
The Billiard Ball Model is John Dalton's idea of what an atom looks like.
The word is spelled billiard, just as you spelled it. The billiard ball rolled smoothly to the corner pocket.
A billiard ball.
Dalton's atomic model was often referred to as the "Billiard Ball Model" because he envisioned atoms as solid, indivisible spheres similar to billiard balls.
The answer is rather simple. Even though a billiard ball is smooth, when it rolls it imparts some of its kinetic energy to the felt covering of the table. That is, the felt heats up a bit as the ball slows down.
The word billiards, though plural in form, is singular in meaning. There is no such thing as a billiard. You can refer to a billiard ball or a billiard table, but in those constructions the word billiard is an adjective, not a noun.
The stroke is the method for sliding the cue to strike the cue ball. A good billiard stroke is very straight and level and continues with a follow through after contact with the cue ball.
Cue ball is part of the Billiard ball collection in New York.