Problem No$.1(50$ points$)$

Given: A hollow square tube is attached to a machine and loaded with an inclined force vec$(F)$ of

magnitude $1\mathrm{.}3$ kips applied at point $B$ with the line of action shown in the diagram

below.

Required: The moment of vec$(F)$ with respect to $($a$)$ point $A$ on the top surface of the square tube,

and $($b$)$ the $z$ axis through the center of the square tube at the section at $A.$