Question

A uniform disk of radius 0.5 m and mass 3.9 kg is rotating about its center of mass. Its moment of inertia about its center of mass is I=(1/2)mR^2. Its angular velocity as a function of time is given by (t)=7kt^6/t1^7 where k = 3.8 rad and t1= 5 s. Find the magnitude of the net torque about the center of mass acting on the disk at t = 8 seconds.

How do I use moment of inertia and angular velocity to find the net torque?