$(25\%)$ Define the bending moments for the beam segments $AB,BC$ and BD loaded as shown in the figure. The cable passes over a small frictionless pulley $($which transfers only loads to the beam and no bending$)$ at C and supports a weight $F_w(kN).(15\%)$ Which cross$-$section should you use $(1$ or $2,$ see figure below$)$ for the span AB if you have a material weak in tension and why?$(5\%)$ What kind of internal forces do we have in segment AB $?$ Is the curvature in AB and BC positive or negative?$(5\%)[$Note: give the answers in terms of $[$:$F_w,a,l_1,l_2$