$11-21.$ Using the LRFD method, select the lightest W$10,16$ ft long beam$-$column in an unbraced frame. Based on a first$-$order analysis, the member supports the following factored loads: $P_{nt}$ load of $148$ k and $P_{it}$ load of $106$ k $.$ The member also supports factored moments: $M_{ntx}$ moment of $92ft-k$ and $M_{ltx}$ moment of $64ft-k.$ The moments are equal at each end and the member is bent in single curvature. There are no transverse loads between the ends.

$K_x=1\mathrm{.}50,K_y=1\mathrm{.}0,P_{\text{s}\text{t}\text{o}\text{r}\text{y}}=2,800k,P_e$ story $x=72,800k,C_b=1\mathrm{.}0$ and $F_y=50$ksi steel. $($Ans$.$ W$1068$ LRFD$)$

$11-21.$ Using the LRFD method, select the lightest W$10,16$ ft long beam$-$column in an unbraced frame. Based on a first$-$order analysis, the member supports the following factored loads: $P_{nt}$ load of $148$ k and $P_{it}$ load of $106$ k $.$ The member also supports factored moments: $M_{ntx}$ moment of $92ft-k$ and $M_{ltx}$ moment of $64ft-k.$ The moments are equal at each end and the member is bent in single curvature. There are no transverse loads between the ends.

$K_x=1\mathrm{.}50,K_y=1\mathrm{.}0,P_{\text{s}\text{t}\text{o}\text{r}\text{y}}=2,800k,P_e$ story $x=72,800k,C_b=1\mathrm{.}0$ and $F_y=50$ksi steel. $($Ans$.$ W$1068$ LRFD$)$