A pulley, consists of a disk of radius R=0.2 m and mass M= 25 kg is mounted on a nearly frictionless axle. A string is wrapped lightly around the pulley, and you pull on the string with a constant force, F = 50 N. If the pulley starts from rest, what is the angular speed at a time ∆ t=2 s later? Assume that the string does not slip on the pulley. Note: Moment of inertia of a disk about an axis through its center of mass is Idisk = (1/2) MR2