a. A uniform disk (m = 401 g, r = 11 cm) is spinning at a
rate of 49.1 rad/s when a ring is dropped on it. If the ring has a
mass M = 0.13 kg and a radius R = 0.06 m and lands such that the
center of the ring aligns with the center of the disk, what will
the final angular velocity of the disk be?
b. A uniform disk (m = 0.40 kg, r = 0.39 m) is spinning at
a rate of 15.7 rad/s. A force is applied to the edge of the disk
and it stops in 2.5 revolutions. What must the magnitude of the
force been?