Flooding of the Chagres River was a problem with the construction of the Panama Canal. During occasional floods, the flowrate near Barbacoas would rise as high as 600,000 gal/s compared to 7500 gal/s in the dry season. If the effects of friction must be considered, determine the diameter needed for a 1500 ft wrought iron pipe to carry away 75,000 gal/s. The water is released at sea level(a drop in elevation of about 200 ft).

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.