Water is flowing at a rate of 500 gal/min in a horizontal pipe. the pipe is 500 ft long and contains two standard 90° elbows and a swing-type check valve. the pressure drop in the pipe line is 0.85 psig. what would be the diameter of the pipe? [density of water is 1000 kg/m: viscosity of water is 1.002 cp; relative roughness of the pipe is 0.00015 ft