PLEASE, SHOW YOUR WORK

1. A hollow disk is rotating about its center at 5 rad/s. Friction is acting on the disk at the axis of rotation producing an angular acceleration of 1 rad/s. How many revolutions will the disk rotate before coming to a stop?

2. A 72.0-kg person pushes on a small doorknob with a force of 5.00 N perpendicular to the surface of the door. The doorknob is located 0.800 m from axis of the frictionless hinges of the door. The door begins to rotate with an angular acceleration of 2.00 rad/s2. What is the moment of inertia of the door about the hinges?

3. An drill rotating at 2247 rpm comes to a stop in 2.2s. How many revolutions did the drill rotate before coming to a stop?

4. A potter's wheel (a solid, uniform disk) of mass 7.0 kg and radius 0.65 m spins about its central axis. A 2.1 kg lump of clay is dropped onto the wheel at a distance 0.41 m from the axis. Calculate the rotational inertia of the system.

5. Two children are sitting on opposing edges of a see-saw. Derive the center of mass of this system.