Q. A Block ' ' is placed on a smooth horizontal surface and a particle is suspended with the help of light rod from point of the block as shown. Now both the block and the particle are given velocity towards left. The block strikes a fixed wall and suddenly stops. Then, (The rod is free to rotate about )

Work, Energy and Power Report Error

A

The smallest velocity for which the particle will swing in a full circle about the point is .

B

The smallest velocity for which the particle will swing in a full circle about the point is .

C

Velocity of point at the highest point of the circle (for the smallest value of ) is zero.

D

Velocity of point at the highest point of the circle (for the smallest value of ) is .

Solution:

As soon as the block hits the wall, the suspension point comes to a stop, while the particle keeps moving with a velocity towards left. In order that it complete a full circle, it must have enough kinetic energy so as to make it to the top of the circle.

i.e.,
Since velocity at the highest point being zero.

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