Problem 2.8. Water and air flow upwards in a conical-shaped vertical pipe. The pipe diameter increases from 1-cm ID at the bottom of the pipe to 10-cm ID at the top. The height of the pipe is 20 m. The water-flow rate is q = 2 10-4 m/s, and the air-flow rate is q = 5 10-4 m/s. The densities of the water and air are 1,000 kg/m and 1.2 kg/m respectively. 10 m B -30 Fig. 2.8-Schematic for Problem 2.5. C