The bob A of a pendulum released from `30^(@)` to the vertical hits another bob 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 therefore A would come to rest and A would come to rest and B would begin to move the velocity of A.
The bob transfer its entire momentum to the ball on the table . The bob does not rise at all .