What would the inertia of the built be also what would the final angular velocity of the disk be ?

Extra Credit: A disk is mounted with its axis vertical. It has radius R = 4 m and mass M = 3 kg. It is initially at rest. A bullet of mass m = 100 g and velocity v = 400 m/s is fired horizontally and tangential to the disk. It lodges in the perimeter of the disk. What angular velocity will the disk acquire? OR. KE. = I@ 2 V : KE