Two identical balls `A` and `B` lie on a smooth horizontal surface, which gradually merges into a curve to a height `3.2 m`. Ball `A` is given a velocity of `10 m//s`, to collide head-on with ball `B`, which then takes up the curved path. What is the minimum coefficient of restitution, `e`, for the collision between `A` and `B` in order that ball `B` reaches the highest point `C` of the curve.

Explanation

Velocity of `B` after collision
`v_(2)((1+e)m_(1)u_(1))/((m_(1)+m_(2)))=((1+e)mxx10)/(m+m)impliesv_(2)=5(1+e)`
Height raised by` B=v_(2)^(2)/(2g)`
Now `v_(2)^(2)/(2g)ge3.2implies((5(1+e))^(2))/(2xx10)ge3.2impliesege3/5`