A cue ball traveling at 3.0 m/s makes a glancing, elastic collision with a targe
ID: 1462504 • Letter: A
Question
A cue ball traveling at 3.0 m/s makes a glancing, elastic collision with a target ball of equal mass that is initially at rest. The cue ball is deflected so that it makes an angle of 30° with its original direction of travel.
(a) Find the angle between the velocity vectors of the two balls after the collision.
90 ° I already found the angle
(b) Find the speed of each ball after the collision.
Your response differs from the correct answer by more than 10%. Double check your calculations. m/s target ball
Your response differs from the correct answer by more than 10%. Double check your calculations. m/s
Explanation / Answer
Initial Velocity of cue ball = 3.0 m/s
Initial Velocity of taeget ball = 0
Final Velocity of cue ball in x direction = vc * cos(30)
Final Velocity of cue ball in y direction = vc * sin(30)
Final Velocity of target ball in x direction = vt * cos(60)
Final Velocity of cue ball in y direction = vt * sin(60)
Using Momentum Conservation -
vc * sin(30) = vt * sin(60)
vc = 1.732 * vt
3.0 = vc * cos(30) + vt * cos(60)
3.0 = 1.732 * vt * cos(30) + vt * cos(60)
vt = 1.5 m/s
vc = 2.6 m/s
Speed of Ball after Collision -
Speed of Cue ball, Vc = 2.6 m/s
Speed of target ball, Vt = 1.5 m/s