The circular arc cam rotates uniformly at 600 rpm and operates a flat-footed reciprocating follower. Base circle radius = 24 mm, nose circle radius = 3 mm, center distance between base and nose circles = 30 mm and distance from pitch circle center to center of curvature of wing circular = 120 mm. The follower retaining spring must be designed so that the spring force at the beginning of the nose is 10% greater than the value required to hold the follower on the cam, and in the full lift position, the spring force is 5% greater than the required value. Find the spring stiffness and the spring force at the zero-lift position if the total mass of the reciprocating parts is 1.25 kg.