Problem $9-21$ Do only LRFD$.$ Address only Moment capacity. $($i$.$e$.$ you

do not have to check shear or deflections$).$

$9-21.$ The cantilever beam shown in Fig. P$9-21$ is a W$21555$ of A$992-$Grade $50$

steel. Lateral bracing is supplied at the fixed end only. The uniform load is a

service dead load and includes the beam self$-$weight. The concentrated loads are

service live loads. Determine whether the beam is adequate using LRFD$.$ Assume $C_b=1\mathrm{.}0.($Ans$.$ LRFD OK$,409\mathrm{.}6ft-k>395\mathrm{.}0ft-k)$