3. See the right Figure. Two disks with radii n; and n; are glued together coaxially. They can rotate around a horizontal, smooth, xed axis passing through the center of the disk and perpendicular to the disk surface, and their moment of inertia about this axis is I. Light ropes are wrapped around both sides of the disks. Objects A and B, with masses mA and mg respectively, are suspended at the lower ends of the ropes. If object A rises with an acceleration aA, prove that the mass of object B is m3 = IaA+mArfl(g+aA) ' THEE7'3 \"A