Question 12 A closed cylindrical tank (P = 1143.8 KPA),5 m in diameter, discharges through a mild horizontal steel pipe, 70 m long and 230 mm diameter, which is connected to the base of the tank. If the end of the pipe is discharged at atmospheric pressure, find the time it takes for the water level in the tank to drop from 3 m to 1 m above the bottom. The viscosity of water is 1 mNs/m2. Use Churchill's friction factor equation