P$1.40=5+10+10+15$

A steel section is shown.

$($a$)$ Determine the location of horizontal ENA $($elastic neutral axis$),\frac{?}{\text{b}\text{a}\text{r}}(y),$ from the top of the section

$($b$)$ Determine the moment of inertia about the horizontal ENA, $I_x$

$($c$)$ Determine the location of horizontal PNA $($plastic neutral axis$),y_p,$ from the top of the section

$($d$)$ Determine the plastic section modulus about the horizontal PNA, $Z_x$