Aenergy storage system based on a flywheel (a rotating disk) can store a maximum of 4.0 mj when the flywheel is rotating at 20,000 revolutions per minute. what is the moment of inertia of the flywheel?

Moment of inertia of the flywheel,          

Explanation:

Given that,

The maximum energy stored on  flywheel,

Angular velocity of the flywheel,

We need to find the moment of inertia of the flywheel. The energy of a flywheel in rotational kinematics is given by :

I is the moment of inertia of the flywheel

On rearranging we get :

So, the moment of inertia of the flywheel is . Hence, this is the required solution.