A horizontal disk, with a moment of inertia of 10 kg* square meters, relative to a vertical frictionless axis through its center, is initially rotating about that axis counterclockwise, as viewed from above with an angular velocity of magnitude 3.0 rad per second. It drops onto another horizontal disk with moment of inertia 20 kg* square meters, which is initally stationary but which is free to rotate without friction about the same axis. The surfaces are rough and the two disks rub together until they reach a common final angular velocity.
a. Is the total angular momentum of the two disks conserved as they move together? Why or why not?
b. Is the total kinetic energy of the two blocks conserved as they rub together? Why or why not?
c. What is the total angular momentum before the collision?
d. What is the common final angular velocity of the disks?
e. What is the ratio of the final to initial total kinetic energy?