A spool of mass m radius r and radius of gyration kG rolls without slipping on an incline whose angle with respect to the horizontal is (theta) A linear elastic spring with constant k and unstretched lenth L0 connects the center of the spool to a fixed wall. Detrmine the differential equation of motion of the spool using the x coordinate which is on the same like as the motion of the spool and determine the natural frequency of the system.