Three disks are spinning independently on the same axle without friction. Their respective rotational inertias and angular speeds are I, w (clockwise); 2I, 3w (counterclockwise); and 4I, w/2 (clockwise). The disks then slide together and stick together, forming one piece with a single angular velocity. What will be the direction and the rate of rotation of the single piece?
Express your answer in terms of one or both of the variables and and appropriate constants. Use a minus sign for clockwise rotation.
See attached file for full problem description.
A very good example to understand the principle of conservation of angular momentum.