A ball moving with a velocity of 6 m/s strikes an identical stationary ball. After collisions each ball moves at an angle of 30^(@)with the original line of motion. What are the speeds of the balls after the collision?

A ball moving with a velocity of 6 m/s strikes an identical stationary

1.	A ball moving with a velocity of 6 m/s strikes an identical stationary ball. After collisions each ball moves at an angle of 30^(@)with the original line of motion. What are the speeds of the balls after the collision?
Answer» Solution : APPLYING the law of conservation of momentum perpendicular to the initial LINE of motion: `0 = mv _(1) sin 30^(@) - mv _(2) sin 30^(@) or v _(1) =v _(2) …(i)` HENCE speed of both will be same after collision. Now ALONG the line of motion: `mv = mv _(1) cos 30^(@) + mv _(2) cos 30^(@).....(ii)` Putting EQUATION (i) in equation (ii) `mv = 2 mv _(1) cos 30^(@) (or) v _(1) = (v)/(sqrt3) = (6)/(sqrt3) = 2 sqrt3 m//s`