Relationship Between Depth and Pressure

Fluid Flow CONTINUITY EQUATION This equation tells us that the pressure exerted by a column of water is directly proportional to the height of the column and the density of the water and is independent of the cross-sectional area of the column. The pressure thirty feet below the surface of a one inch diameter standpipe is the same as the pressure thirty feet below the surface of a large lake. Example 1: If the tank in Figure 1 is filled with water that has a density of 62.4 lbm/ft³, calculate the pressures at depths of 10, 20, and 30 feet. Solution: P r h g g_c P 10 feet � � � � � � 62.4^lbm ft³ 10 ft � � � � � � � � � � � � � � 32.17 ft sec² 32.17 lbm ft lbf sec² 624^lbf ft² � � � � � � � � 1 ft² 144 in² 4.33 lbf in² P 20 feet � � � � � � 62.4^lbm ft³ 20 ft � � � � � � � � � � � � � � 32.17 ft sec² 32.17 lbm ft lbf sec² 1248^lbf ft² � � � � � � � � 1 ft² 144 in² 8.67 lbf in² Rev. 0 Page 5 HT-03