Question

Example: The bob $A$ of a pendulum released from ${30}^{\circ }$ to the vertical hits another bob $B$ of the same mass at rest on table as shown in figure. How high does the bob $A$ rise after the collision? Neglect the size of the bob and assume the collision to be elastic.

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

The two bobs $A$ and $B$ are of the same mass and the collision between them is elastic. Thus, after collision, the two bobs will interchange their velocities. Obviously, the bob $A$ would come to rest and does not rise at all. But bob $B$ would move with the velocity of $A$.