1. Air at standard temperature and pressure flows at a rate of 7.0 cfs through a horizontal, galvanized iron duct that has a rectangular cross-sectional shape of 12 in. by 6 in. Estimate the pressure drop per 200 ft of duct.
2. Air flows through a rectangular galvanized iron duct of size 0.30 m by 0.15 m at a rate of 0.068 m3 /s. Determine the head loss in 12 m of this duct.