Question

What constant torque should be applied to the disc of mass 10kg and diameter 50cm so that it acquires an angular velocity of 2rad/sec in 4sec ?? The disc is initially at rest and rotates about an axis through the centre of the disc and in a plane perpendicular to the disc?

Answer 1

Torque = moment of inertia *

Omega

You've been given the mass and radius and the fact that it is a disk . Calculate the moment of inertia by 1/2*m*r^2 .

Then calculate Omega by 2 rad/4 sec .

Place them in the formula

You'll get your answer