Example $5$

A floor system for use in an office building utilizes $45-$foot$-$long floor beams

spaced at $9$ feet. The floor will be subjected to a service dead load of $50$ psf

and a unreduced service live load of $80$ psf $.$ Using LRFD load combinations,

what is most nearly the maximum factored bending moment on a given floor

beam?

A$.126$ ft $-$kip

B$.363$ ft $-$kip

C$.428$ ft $-$kip

D$.800$ ft $-$kip