a small disk of radius r=2.00 cm has been glued to the edge of a larger disk of radius R=9.00 cm so that the disks lie in the same plane. The disks can be rotated around a perpendicular axis through point O at the center of the larger disk. The disks both have a uniform density (mass per unit volume) of 1.40 × 103 kg/m3 and a uniform thickness of 7.00 mm. What is the rotational inertia of the two-disk assembly about the rotation axis through O?