A uniform disc of radius R and mass M is free to rotate only about its axis. A string is wrapped over its rim and a body of mass m is tied to the free end of the string as shown in the figure. The body is released from rest. Then the acceleration of the body is :
As we learnt in
Analogue of second law of motion for pure rotation -
- wherein
Torque equation can be applied only about two points
(i) centre of motion.
(ii) point which has zero velocity/acceleration.
Short trick
Option 1)
This is the correct oiption.
Option 2)
This is an incorrect option.
Option 3)
This is an incorrect option.
Option 4)
This is an incorrect option.