Question
A stick of length L and mass M lies on a frictionless horizontal surface on which it is free to move in any way. A ball of mass m moving with speed V collides elastically with the stick as shown in fig below. If after the collision, the ball comes to rest, then what should be the mass of the ball?
m = 2M
m = M
m= M/2
m = M/A
Solution
D.
m = M/A
Applying the law of conservation of momentum
mV = MV ... (i)
By conservation of angular momentum
As the collision in elastic, we have