Q. A 0.150 kg billiard ball (A) is rolling toward a stationary billiard ball (B) at 10.0 m/s. After the collision, ball A rolls off at 7.7 m/s at an andle of 40.0 degrees clockwise from its original direction. What is the speed and direction of Ball B after the collision? Known: M of A = .150 kg M of B = .150 kg Vi of B = 10.0 m/s Vf of A = 7.7 m/s[70degrees clockwise] Implied: Vi of A = 0 m/s Ff = 0N Unknown: Vi of B = ? I started out using the law of conservation of energy but I messed up somewhere early and got fully lost...I know you need to use this method to conserve the momentum of each object but I just can't remember how, can someone start please?