posted by Beth .
The disk has mass 10kg and radius 0.25m. The rod has mass 5kg, length 0.5m and radius 0.05m. The rod is split down the middle and is hinged so that its two halves can lay flat against the disk. Suppose that the disk and rod are initially rotating at 3.0rad/s around the axis that is shown in the first diagram. What is the angular speed of the disk and rod after the rod flies open?