2. (15 points) For the four-stringer thin-walled channel section shown below, please find (a) horizontal y-coordinate of the centroid, assuming (0,0) at the bottom left corner stringer, (b) shear flow of each segment $q_1$, $q_2$, $q_3$, and (c) the y-coordinate of the shear center $y_{BC}$, when $V_z = 5000$ N, $h = 40$ cm, and $A_0 = 10$ cm$^2$.