$2.$ For Model Problem $10\mathrm{.}2$ related to the Secant Formula, consider a uniform column $\backslash ($ A B $\backslash )$ with a $10-$feet structural tube section, as shown in Figure $2.$

Determine:

a$)$ The permissible centric load for the column and the corresponding normal stress using Euler's formula with a safety factor of $2\mathrm{.}5.$

b$)$ The horizontal deflection at the top end of the column and the maximum normal stress when the permissible load found in part $($a$)$ is applied at a point $0\mathrm{.}90$ in from the column's geometric axis.

Figure $2.$ Adaptation of Model Problem $10\mathrm{.}2.$