A large disk of mass M and radius R is spinning like a CD of merry-go-round - that is, about an axis perpendicular to the plane of the disk. It is rotating at an angular velocity ? (initial). At some instant, a sphere of mass M/4 , which is initially not rotating, is dropped onto the disk at a distance of 3R/ 4 from the center. The sphere sticks to the disk and begins rotating with it. Find the final velocity of the disk-sphere combination.

^^^ the ? mark is the lowercase "omega"

Add the two I, using the parallel axis theorem.