A rectangular road sign is supported on a hollow post as shown. The weight of the sign is $6\mathrm{.}7$ kN $.$ The face of the sign is subjected to a uniform wind force of $500\frac{N}{m^2}.$ A cross$-$section of the post at $1\mathrm{.}2$ m below the bottom of the sign $(P)$ is shown. Identify all the different loads and their corresponding resulting stresses into the pole at point A located at $P.$

Use the standard formulas below

$($a$)$ determine the combined state of stress $($for point $A)$

$($b$)$ show the stress state on unit $3-$d cell element $($for point A$)$

$($c$)$ show the stress tensor $($for point A$)$

Neglect any shear due to transverse load.