A $20$ in diameter galvanized steel $($smooth $)$ straight duct section conveys air at $3000$ft $*3/$ m $*$ in $.$ It is $45$ ft long $.$ A$)$Determine the pressure loss $,$ in inches of w$.$c$.$ B$)$ Determine the average velocity of air flowing through the duct. C$)$ dentify a cost $-$effective rectangular duct section with an equivalent pressure loss that has a side depth of $12$ in