$1\mathrm{.}2\backslash$times $10$ and two $2\backslash$times $6$b$\_($f$)=6$in$.,$t$\_($f$)=$t$\_($w$)=2$in$.,$d$\_($w$)=10$in$\mathrm{.}880-$lb load at the center of a $16-$ ft span, determine:

$($a$)$ the maximum spacing ss$=3\mathrm{.}15$in $\backslash$tau $\_($max$)$ in the I $-$beam. $\backslash$tau $\_($max$)=20\mathrm{.}5\backslash$psi