Problem involving conservation of momentum in two dimensions?

Question

A billiard ball moving at a speed of 2.2 m/s strikes an identical stationary ball with a glancing blow. After the collision, one ball is found to be moving at a speed of 1.1 m/s in a direction making a 60 degree angle with the original line of motion.

Find the velocity of the other ball, and explain how you got your answer.

Answer 1

Open your physics book or try "the physics classroom" a web site with good definitions. answer is 1.1 m/s. try the site below

Answer 2

v1y2 = 1.1sin60
v1x2 = 1.1cos60
v2y2 = -1.1sin60 (0 = v1y2 + v2y2)
2.2*m = m*1.1cos60 + mv2x2
v2x2 = 1.1(2-cos60)