$1\mathrm{.}310201\mathrm{.}31020$electrons flow through a cross section of a$2\mathrm{.}1-$mmmm$-$diameter$$iron wire in$6\mathrm{.}0$s The truss in the following figure has a $\backslash (2\backslash$times $4\backslash )$ lower chord of Select Structural SPF $-$ South $($Spruce$-$Pine$-$Fir$)$ and a $\backslash (2\backslash$times $10\backslash )$ top chord of No$.2$ Hem$-$fir. The loads shown are the results of $\backslash ($ D$=20\backslash$mathrm$\{$psf$\}\backslash )$ and $\backslash ($ S$=55\backslash )$ psf acting vertically over the $20\text{'}$ span. There is no reduction of area for fasteners. $\backslash ($ C$\_\{$M$\}=\backslash )\backslash ($ C$\_\{$t$\}=$C$\_\{$i$\}=1\mathrm{.}0\backslash ).$ Joints are assumed to be pin$-$connected. Trusses are spaced $4$ ft on center. The top of the truss is fully supported along its length by roof sheathing. Check the combined compression and bending in the top chord using LRFD$.$

Please note that this is the same structure of your Homework $\backslash$#$5$ Problem $1.$ Follow this structural analysis guideline to estimate the bending moment in the top chord and additional distributed force at the top chord cause by

Guideline on the Structural Analysis portion: Since the actual loading is a distributed forces acting on a projecting plane on the top chords, this distributed force will induce bending moment on the top chord. In Homework $5$ Problem $1,$ we have done an approximation of the axial force in the top chord $($see solution for Homework $5$ Problem $1).$ Therefore, the remaining structural analysis to be completed is by calculating the maximum moment at the top chord $\backslash ($ A D $\backslash )$ or $\backslash ($ F C $\backslash )($note the symmetric characteristic of the structure and the loadings$).$ To calculate the maximum moment, please consider a simply supported model $($because the truss member is pinned at both ends$)$ with distributed forces acting on the projected plan $($See Figure $2).$ For ease of analysis, you may want to project the distributed forces to be perpendicular with the member $(\backslash (\backslash$underline$\{$w$\}\_\{$w$\_\{1\}\}\backslash )).$ We will ignore the component of distributed forces along the member $(\backslash (\backslash$underline$\{$w$\}\_\{$u x$\}\backslash ))$ in this analysis. In general, $\backslash (\backslash$underline$\{$w$\}\_\{$u$\_\{$j $\backslash$underline$\{$g$\}\}\}\backslash )$ will increase the axial load we obtained from Homework $5$ Problem $1.$ So$,$ first calculate the $\backslash ($ y $\backslash )$ component $(\backslash (\backslash$underline$\{$w$\}\_\{\backslash$underline$\{$u$\}$ v$\}\backslash ))$ of this distributed force

Figure $1$ Roof truss structure under dead and snow load acting on the projected plane.

Figure $2$ Simplified moment to calculate the maximum moment on the top chord