A large disk with a radius of 20 cm has a string attached to its edge, which is hanging over a table with a 200 g mass attached to it. The mass is dropped 1 m, and reaches a speed of 1 m/s after the drop. Using the torque acting on the disk, determine the moment of inertia of the disk. Assume the disk rotates about its center of mass. (Use ? = I? = rF).