$9-5$ For the cross sections shown, compute:

$($a$)$ the gross moment of inertia, $I_g$;

$($b$)$ the location of the neutral axis of the cracked section and I cr; and

$($c$)Ie$ for $Ma=0\mathrm{.}55Mn.$

The beam has a $1\mathrm{.}5in.$ of clear cover and No$.3$ stirrups. The concrete strength is $4000$psi $f_y=60$ksi. $6$ No$.8$ bars