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.

33. Based on Figure 2, the relationship between(in kPa) and D (in m) for the water in the tank is best represented by which of the following equations?

Answer and Explanation

Your Answer is

Correct Answer is A

Explanation

Method 1: Stupid but learning scum General method: Look at figure 2, take any point on the PL line segment. For example, when the abscissa is 10, the ordinate is about 100, and PL=10D, which is the closest to option A

Method 2: Powerful learning method: liquid pressure P=ρgh, h depth in this article The middle is D, so P=ρgD

G=9.8, ρwater=1 and P=9.8D