The compressed air requirements of a manufacturing facility are met by a 120-hp compressor that draws in air from the outside through an 9-m-long, 22-cm-diameter duct made of thin galvanized iron sheets. The compressor takes in air at a rate of 0.27 m3 /s at the outdoor conditions of 15°C and 95 kPa. Disregarding any minor losses, determine the useful power used by the compressor to overcome the frictional losses in this duct, find the friction factor by Colebrook equation, Haaland equation and the Moody diagram. Use the obtained answers to get the useful power. Use Swamee & Jain equation to get the head loss and the useful power. Compare between the different answers and comment on the error by comparing with the most accurate method of the four used.