Torricelli's barometer used mercury. Pascal duplicated it using French wine of density $984 \; kg \; m^{-3}$. Determine the height (in $m$) of the wine column for normal atmospheric pressure.

When an airplane flies at a higher altitude,it is not advisable to keep a fountain pen in one's pocket. Why?

The density of the liquid filled in the container is $900 \ kg/m^{3}$. Calculate the force exerted on the bottom of the container. (Given: $g = 10 \ m/s^{2}$) (in $N$)

$A$ submarine is designed to withstand an absolute pressure of $100 \text{ atm}$. How deep can it go below the water surface (in $\text{ m}$)? (Consider the density of water = $1000 \text{ kg/m}^3$, $1 \text{ atm} = 1 \times 10^5 \text{ Pa}$, and gravitational acceleration $g = 10 \text{ m/s}^2$)

What are the difficulties arising from using water in a barometer instead of mercury?

If the atmospheric pressure is $P_a$,then the pressure $P$ at depth $h$ below the surface of a liquid of density $\rho$ open to the atmosphere is: