Determine the minimum size smooth rectangular duct with an aspect ratio of 3 that will 1 m^3/s 10 degree C air with a head loss of 25 mm of water per 100 m of duct. A new industrial plant requires a water flow rate of 5.7m^3/min. The gage pressure in the water main, located in the street 50 m from the plant, is 800 a. The supply line will require installation of 4 elbows in a total length of 65 m. The gage pressure required in the plant is 500 kPa. What size, galvanized iron line should be installed?