posted by Artin .
A solid uniform disk of mass 21kg and radius 85cm is at rest flat on a frictionless surface. A string is wrapped around the rim of the disk and constant force of 35N is applied to the string, which does not slip on the rim, in the positive x direction. (a) In what direction does the center of mass move? When the disk has moved a distance of 5.5m ,determine (b )how fast it is moving, (c) how fast it is spinning,and (d) how much string has unwrapped from the rim.