A uniform disc of mass M and radius R is mounted on an axle supported in frictionless bearings. A light cord is wrapped around the rim of the disc and steady downward pull T is exerted on the cord. The angular acceleration of the disc is :
Answer & explanation
Correct answer: option 3
Torque exerted on the disc : \(\tau\)
\(\tau = TR\)
Now, \(\tau = I \alpha\)
\(\alpha = \frac{\tau}{I}\)
\(\alpha = \frac{TR}{\frac{1}{2} MR^2}\)
\(\alpha = \frac{2T}{MR}\)