For the spring-mass-pulley system of figure 5-37, the moment of inertia of the pulley about the axis of rotation is J and the radius is R. Assume that the system is initially in equilibrium. The gravitational force of mass m causes a static deflection of the spring such that kd=mg. Assuming thst the displacement y of mass m is measured from the equilibrium position, obtain a state-space representation of the system. The external force u applied to mass m is the input and the displacement y is the output of the system.