question_answer 17)

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 Fig. 6.51. How high does the bob A rise after the collision ?            Neglect the size of the bobs and assume the collision to be elastic.                    

Answer:

When the bob A hits bob B on the table, it transfers its entire K.E. to the bob B because the collision is elastic. The bob A comes to rest at the location of B while the bob B begins to move with the velocity of A.