The bob A of a simple pendulum released from `30^(@)` to the vertical hits another bobo B of the same mass at rest on a table as shown in figure. How high does the bob A rise after the collision ? Neglect the size of the bobs and assume the collision to be elastic.

Explanation

Since collision is elastic therefore A would come to rest and B would begin to move with the velocity of A.

The bob transfers its entire momenum to the ball on the table. The bob does not rise at all .