Pool players often pride themselves on their ability to impart a large speed to
ID: 1414716 • Letter: P
Question
Pool players often pride themselves on their ability to impart a large speed to a pool ball. In the sport of billiards, event organizers often remove one of the rails on a pool table to allow players to measure the speed of their break shots (the opening shot of a game in which the player strikes a ball with his pool cue). With the rail removed, a ball can fly off the table. As the only participant with a physics background, they have placed you in charge of determining the speed of the players' break shots.
The top of the pool table is 0.710 m from the floor. The placement of the tape is such that 0 m is aligned with the edge of the table (as shown). The winner of the competition wants to know if he has broken the world record for the break shot of 32 mph (about 14.3 m/s). If the winner's ball landed a distance 4.25 m from the table edge, calculate his break shot speed.
At what speed did his pool ball hit the ground?
Explanation / Answer
TIME for ball to drop 0.77 metre = sqrt.(2h/g) = 0.396 sec. (9.8 used as g).
Break shot V if ball hits the ground 4.25 metres from table = (4.25/0.396) = 11.49m/sec.
No record.
Remember horizontal V and drop time are independent of each other. A ball will drop the same height in the same time regardless of its horizontal V.
Oh, didn't notice speed at ground bit (edit).
Its horizontal component is 11.49m/sec., it vertical component is sqrt.(2gh) = 3.885m/sec.
V at ground contact = sqrt. (11.49^2 + 3.885^2) = 12.129m/sec.
Ans- His pool ball will hit the ground at 12.129 m/s