Two Torques on a Disk Problem
A solid horizontal disk with a mass of 3.00 kg and radius of 75.0 cm rotates on a frictionless bearing at its center. Two horizontal forces are applied to the disk at different locations with different angles. Force F1 is 15.0 N and is applied at an angle of 36.00 relative to due east. F1 is applied to a point that is 28.0 cm directly north of the disk's center. Force F2 is 22.0 N applied due east. F2 is applied to a point that is 63.0 cm from the disk's center and is 16.00 east of due south.
   (A) What is the net torque on the disk initially ?
   (B) What is the initial angular acceleration of the of the disk ?
   (C) What is the magnitude of a third force F3, applied tangentially to the rim of the disk -- needed to keep the disk from rotating ?