P$8\mathrm{.}13$ Two uniformly distributed loads $w=3,600\frac{lb}{ft}$act on the simply supported beam shown in Figure P$8\mathrm{.}13$a$.$ The beam spans are $a=8ft$ and $L=16ft.$ The beam cross section shown in Figure P$8\mathrm{.}13$b has dimensions of $b_1=16$ in$.,d_1=6$ in$.,b_2=10in.,$ and $d_2=10in.$ Calculate the maximum tensile and compressive bending stresses produced in segment $BC$ of the beam.