A 30-lb slender rod AB is 5 ft long and is pivoted about a point O which is 1 ft from end B. The other end is pressed against (NOT connected with) a spring of constant k = 150 lb/ft until the spring...

Extracted text: A 30-lb slender rod AB is 5 ft long and is pivoted about a point O which is 1 ft from end B. The other end is pressed against (NOT connected with) a spring of constant k = 150 lb/ft until the spring is compressed 1 ft. The rod is then in a horizontal position. The mechanism is designed such that no interference occurs during all motions. If the rod is released from rest at this position, when it rotates 45°, determine: a) The angular velocity of rod AB. b) The angular acceleration of rod AB, as well as the magnitude of the reaction force at O. 5 ft 1 ft B