Problem 4 (40 points) Consider the system shown in Figure 3 (a). The damping ratio of this system is 0.158 and the undamped natural frequency is 3.16 rad/sec. To improve the relative stability, we employ a tachometer feedback. Figure 3 (b) shows such a tachometer-feedback system. (a) Determine the value of Kh so that the damping ratio of the system is 0.5. b) Write a MATLAB code to draw the unit-step response curves for both the original and the tachometer feedback systems. (c) Write a MATLAB code to draw the error-versus-time curves for the unit-ramp response of both systems R(s) 10 C(s) R(s) C(s) 10 Kh Figure 3