Chapter 8, Problem 2RQ

How does the pressure exerted by a liquid change with depth in the liquid? How does the pressure exerted by a liquid change as the density of the liquid changes?

To determine

The variation in pressure exerted by a liquid change with depth in the liquid and as density of the liquid changes.

Answer to Problem 2RQ

The pressure exerted by a liquid increases as the depth of the liquid increases and as density of the liquid increases, pressure also increases.

Explanation of Solution

Write the expression for the liquid pressure.

$\text{Liquid}\text{Pressure}=\text{Weight}\text{density}\times \text{depth}$

From the above expression, it can be observed that the liquid pressure varies linearly with the depth. It means that, as the depth in the liquid increases, the pressure at that point also increases. If a swimmer goes deep into the water, it will experience greater pressure as compared to the surface of the water. Moreover, the density of the liquid is also responsible for the change in liquid pressure. It means, as the density of the liquid is increasing, the pressure of the liquid also increases. For example, the pressure at the same point in the tube will be different for saltwater and water.

Conclusion:

Therefore, the pressure exerted by a liquid increases as the depth of the liquid increases and as density of the liquid increases, pressure also increases.