The circular arc cam rotates uniformly at 600 rpm and operates a flat-footed reciprocating follower. The base circle radius= 24 mm, the nose circle radius= 3 mm, the center distance between the base and nose circles 30 mm and the distance between the pitch circle center to the center of curvature of the circular flank= 120 mm. The follower retaining spring is to be designed so that at the beginning of the nose, the spring force 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 o the reciprocating parts is 1.25 kg.