$22\mathrm{.}1.$ A rectangular concrete beam with width $b=275mm$ and total depth $h=700mm$ is posttensioned using a single parabolic tendon with an eccentricity of $195mm$ at midspan and $0mm$ at the simple supports. The initial prestress force $P_t=1500kN,$ and the losses $16\%.$ The member is to carry superimposed dead and live loads of $4\mathrm{.}5$ and $15k\frac{N}{m},$ respectively, uniformly distributed over the $12m$ span. Specified concrete strength $f_c^{\text{'}}=35$MPa, and at the time of transfer $f_{c\text{'}}^{\text{'}}=28$MPa. Determine the flexural stress distributions in the concrete at midspan:

$($a$)$ for initial conditions before application of superimposed load and

$($b$)$ at full$-$service load. Compare with the ACI limit stresses for Class U members. Please solve this civil engineering question in detail, dont just give explanations and draw the skech too and i'll give a like