Passage VI

The pressure,, exerted by a liquid varies with the depth, D, below the surface of the liquid and with the liquid’s density, ρ. If a tank of liquid is open to the atmosphere, the total pressure,, at D equalsat D plus the atmospheric pressure,.

Table 1 lists ρ, in kilograms per cubic meter (kg/m³), for 4 liquids at 25℃.

Figure 1 shows, for D = 10 m, a graph of (in kilo-pascals, kPa) versus ρ (1 kPa = Pa =newtons/㎡). Figure 2 shows a graph of versus D and a graph ofversus D for 25℃ water in a tank that was open to the atmosphere on a particular day.