MATLAB: Can you tell me what’s wrong with the script I wrote for a Transfer function for a closed-loop feedback system with disturbances? Thank you.

transfer function

This is the script I wrote for the transfer function for in the picture.
clear all;
figure;
for K = [5,10,50]
Tnum=[K K 0];
Tden=[1 16 21.5+K K+97.5];
T=tf(Tnum,Tden);
t=[0:0.1:10];
[y,t]=step(T,t);
plot(t,y);
hold on;
end
title('Unit Step Response for K= 5,10,50');
xlabel('Time(sec)'),ylabel('Step Response');
grid on;
grid minor;
I Know it is not correct because the output is not the same as the solution in the book. What am I doing wrong?

Best Answer

If you look at your T it is a second order transfer function.
I think your Tnum should be [K K] and not [K K 0]