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Motion In A Plane

Question
CBSEENPH11020882

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 

mV (L/2) = ML212 ω .. (ii)

As the collision in elastic, we have

12mV2 = 12MV2 + 12Iw2   (iii)..substituting the values, we getm = M/4