A particle of mass m is embedded at the periphery of the otherwise uniform disk of mass M and radius r as shown. The disk starts from rest and does not slip on the rough incline. (a) For the position shown, what condition on m will cause the disk to begin to roll up the incline? (b) If m = 4M, determine the initial angular acceleration of the disk and the minimum value of the coefficient of static friction required for the no-slip condition.