A 4-kg slender rod is welded to the edge of a 3-kg uniform disk as shown. The assemble rot...

A 4-kg slender rod is welded to the edge of a 3-kg uniform disk as shown. The assemble rotates about A in a vertical plane under the combined effect of gravity and of die vertical force P. Knowing that at the instant shown die assembly has an angular velocity of 12 rad/s and an angular acceleration of 36 rad/s2 both counterclockwise, determine (a) the force P, (b) the components of the reaction at A.