Question

a fluid with a vapor 0.4 pascal and the specific gravity of 14 is used in a barometer. the fluids column height is 0.8m.find the atmospheric pressure in kpa

Answer 1

Density of the fluid $\rho$ = specific gravity $\times$ density of water $=14\times 1000=14000kg/m^3$

Let $P_v=$ vapor pressure=0.4.

From the principle of barometer, we have $\rho gh=P_{atm}-P_v$

$P_{atm}=\rho gh +P_v=14000\times 9.8\times 0.8 +0.4=109760.4Pa$

$P_{atm}=109.7604kpa$