AIR 1 WATER Mercury Oil The water in a tank is pressurized by air, and the pressure is measured by a multi-fluid manometer, as shown in the figure. The tank is located on a mountain at an altitude of 1,400 m, where the atmospheric pressure is 85.6 kPa. Determine the air pressure in the tank (in "kPa" absolute), if h₁ = 0.1 m, h₂ = 0.2 m, and h = 0.35 m. Take the densities of water, oil, and mercury to be 1,000 kg/m³, 850 kg/m³, and 13,600 kg/m³, respectively. Solution The pressure in a pressurized water tank is measured by a multi-fluid manometer. The air the tank is to be determined. Assumption pressure in The air pressure in the tank is uniform (its variation with respect to "height" is negligible), and thus the pressure at the air-water interface can be determined. Properties The densities of water, oil, and mercury are: 1,000 kg/m³, 850 kg/m³, and 13,600 kg/m³, respectively. Analysis