For the following two problems, use the Darcy$-$Weisbach equation and ignore minor losses.

P$6\mathrm{.}41$ Two reservoirs, which differ in surface elevation by $40$ m $,$ are connected by $350$ m of new pipe of diameter $8$ cm $.$ If the desired flow rate is at least $\backslash (130\backslash$mathrm$\{$~N$\}/\backslash$mathrm$\{$s$\}\backslash )$ of water at $\backslash (20^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ),$ can the pipe material be made of $($a$)$ galvanized iron, $($b$)$ commercial steel, or $($c$)$ cast iron? Neglect minor losses.