Angle Between Velocities After Elastic Collision · CAP 2008 #Q13
Physics · mechanics
Problem
Two identical balls with completely smooth surfaces are moving uniformly in free space without rotation. At some moment, they undergo a perfectly elastic glancing collision. After the collision, the angle between the two vectors of velocities is
(a) 30°
(b) 45°
(c) 90°
(d) Impossible to answer without knowledge of the angle between the two velocities before the collision.