Question

The hydrostatic pressure due to a liquid filled in a vessel at a depth 0.9 m is 3.0 N m-2. What will be the hydrostatic pressure at a hole in the side wall ofthe same vessel at a depth of 0.8 m.

Answer 1

Let the area of cross section be uniform and equal to A. Let the density be d.
Pressure at a depth 0.9m = 0.9 d g = 3.0 N/m^2
             d g = 10 /3  units

Just outside the hole the pressure is the atmospheric pressure itself. P_atm.
Just inside the hole the pressure will be = 0.8 * d g = 8/3  N/m^2, more than atmospheric pressure.

Total pressure = P_atm = 10^5 Pa + 8/3 Pa