Given: The rectangular tube is subjected to the $9$ kip force located $2\mathrm{.}85"$ from the center of the cross$-$section. If the material is aluminum with a yield strength, ${}_Y=37$ksi. The wall thickness is $0\mathrm{.}3$ inches.

Find: Determine the factor of safety at $H$ and $K$ according to:

a$)$ The maximum shear$-$stress theory

b$)$ The maximum$-$distortion energy theory