A 12 in. Sch. 40 pipe, $60 \mathrm{ft}$ long, discharges water at $1 \mathrm{~atm}$ pressure from a reservoir. The pipe is horizontal, and the outlet is $12 \mathrm{ft}$ below the surface of the water in the reservoir.

(a) What is the flow rate, in gpm?

(b) In order to limit the flow rate to $3500 \mathrm{gpm}$, an orifice is installed at the end of the line. What should the diameter of the orifice be?

(c) What size pipe would have to be used to limit the flow rate to $3500 \mathrm{gpm}$ without using an orifice?