$(20$ pts$)$ In the figure shown $($situation A and B$),$ a beam $7\mathrm{.}5m$ long are subjected to a uniform load of $5k\frac{N}{m}.$ The prestressing force of $200kN$ is located $60mm$ from the underside of the beam. Assume prestress losses of $"$x$"\%,$ and a concrete specific gravity of $"y".$

Let $x=$ square root of the cube root of your student number

$y=$ the quotient of the square root of the cube root of your student number, and ten

SITUATION A$.($Beam A$)$

SITUATION B$.($Beam B$)$

In both situation,

a$.$ what is the resultant stress at the top fiber $($psi$)$

b$.$ what is the resultant stress at the bottom fiber $($psf$)$