In a pool game, the cue ball, which has an initial speed of 7.0 m/s, make an ela

Question

In a pool game, the cue ball, which has an initial speed of 7.0 m/s, make an elastic collision with the eight ball, which is initially at rest. After the collision, the eight ball moves at an angle of 35° to the original direction of the cue ball.

(a) Find the direction of motion of the cue ball after the collision.
?    ° (from the original line of motion)

(b) Find the speed of each ball. Assume that the balls have equal mass.
?   m/s (cue ball)
?   m/s (eight ball)

answer such as 60, 2.50 and 4.33 are WRONG! as presented at Chegg/

Explanation / Answer

elastic collision conserve both momentum and energy

m*vci = mv_8 + mvc

1/2*m*(vci)^2 = 1/2*m*(v_8)^2 + 1/2 * m * (vc)^2

part a )

alpha + theta = 90

alpha = 90 -35 = 55 degree

part b )

initially momentum in y direction = 0

Py8 - Pyc = 0

mv8sin35 = mvc*sin55

v8 = 1.428 vc .... (1)

in x direction

Px8 + Pxc = mvi

v8 * cos35 + vc * cos55 = 7

0.82 * v8 + 0.57 vc = 7

from 1 put hte value of v8

1.428 vc + 0.57 vc = 7

vc = 3.5 m/s

v8 = 1.428 *vc

v8 = 4.998 m/s

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.