E9.28 A unity feedback system has the loop transfer function

10 L(s) = G(s)G(s) = s(s +0.8) (a) Determine the phase margin for the system. (b) Use the phase margin to estimate the damping ratio, and predict the percent overshoot. (c) Calculate the actual response for this system, and compare the re- sult with the part (b) estimate.