Two disks are mounted (like a merry-go round) on low friction bearings on the same axle and can be brought together so that they couple and rotate as one unit. The first disk, with rotational inertia 3.30 kg . m 2 about its central axis, is set spinning counterclockwise at 450 rev/min. The second disk, with rotational inertia 6.60 kg . m 2 about its central axis is set spinning counterclockwise at 900 rev/min. They then couple together. a) What is their angular speed after coupling