When a ceiling fan rotating with an angular speed of 1.65 rad/s is turned off, a frictional torque of 0.263 N·m slows it to a stop in 4.75 s. What is the moment of inertia of the fan?

Answer 1

First get the angular deceleration rate, alpha, using
alpha * 4.75 s = 1.65 rad/s
alpha = 0.347 rad/s^2

Then use Torque = I * alpha

Solve for I. You know the torque T already