In the sport of billiards, event organizers often remove one of the rails on a p
ID: 1427825 • Letter: I
Question
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). The top of the pool table is 0.910 m from the floor. The placement of the tape is such that 0 m is aligned with the edge of the table. 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 3.65 m from the table edge, what is his break shot speed?
Explanation / Answer
along vertical
acceleration ay = -g = -9.8 m/s^2
displacement y = -0.91 m
from equation of motion
y = voy *t + 0.5*ay*t^2
t = sqrt(2*0.91/9.8)
t = 0.431 s
along horizantal
x = v*t
v = x/t = 3.65/0.431 = 8.5 m/s <<<<_--------------answer
v < 14.3 m/s record was not broken