For a rectangular Douglas fir section, a cantilever beam with a $10-$ft span will carry a uniform load of $750I\frac{b}{f}t\mathrm{.}5$ required and A required are:

$($Select two answers$)$

Select $2$ correct answer$($s$)$

A required $=119$ in ${?}^2$

$S$ required $=311$ in ${?}^3$

A required $=311$ in ${?}^2$

$S$ required $=119i{n}^3$

$S$ required $=419i{n}^3$

$S$ required $=419$ in ${?}^2$

Question $2(9$ points$)$

$$ Saved

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According to the answers above $($in Q$1),$ select the lightest rectangular Douglas fir section, and its $S_{\text{e}\text{x}\text{t}\text{r}\text{a}}\%$ and $A_{\text{e}\text{x}\text{t}\text{r}\text{a}}\%$ are:

$($Select $3$ answers$)$

Select $3$ correct answer$($s$)$

$820$ Douglas Fir

$A_{\text{e}\text{x}\text{t}\text{r}\text{a}}\%=23\mathrm{.}4\%$

$S_{\text{e}\text{x}\text{t}\text{r}\text{a}}\%=10\mathrm{.}6\%$

Aextra $\%=10\mathrm{.}6\%$

$818$ Douglas Fir

$618$ Douglas Fir

$S_{\text{e}\text{x}\text{t}\text{r}\text{a}}\%=23\mathrm{.}4\%$

Aextra $\%=37\%$

$S_{\text{e}\text{x}\text{t}\text{r}\text{a}}\%=13\mathrm{.}4\%$