Question

A beaker contains a liquid of density $\rho$ upto a height $h$, such that $P$ is the atmospheric pressure and $g$ is the acceleration due to gravity.
Answer the following questions:
a) What is the pressure at the free surface of the liquid?
b) What is the pressure at the base of the beaker?
c) What is the lateral pressure at the base on the inner walls of beaker?

Answer 1

$\left(a\right)$ Pressure at free surface of liquid is the atmospheric pressure itself since $P=P_A+\rho gh$ and for height $=0$, the pressure $P$ $=P_A$.

$\left(b\right)$ At the base of the beaker of height $h$ and density of liquid $\rho$, the pressure $P=P_A+\rho gh$

$\left(c\right)$ Since the pressure exerted on the lateral walls is balanced by a normal reaction by walls onto the liquid, these forces must be equal and since pressure in fluids acts equally in all the directions, thereby implying $P=P_A+\rho gh$