Question

a billiard ball moving at 4.0 m/s strikes another billiard ball at rest and moves off at 3.46 m/s in a direction of 30 degrees from the original of the motion. What is the velocity of the target ball?

Answer 1

M1*V1 + M2*V2 = M1*V3 + M2*V4
M1 = M2?
M1*4 + M1*0 = M1*3.46[30o] + M1*V4
Divide both sides by M1:
M1*4 = M1*3.46[30] + M1*V4
4 = 3.46[30] + V4
V4 = 4 - 3.46[30] = 4 - 3 - 1.73i = 1-1.73i = 2.0m/s[300o] = Velocity of target ball.