Explain Atmospheric Pressure (Patm)
Atmospheric Pressure is the pressure exerted by atmospheric air on any surface. It is calculated by a barometer. The standard values of it are;
1 Patm = 760 mm of Hg i.e. column or height of mercury
= ρ.g.h. = 13.6 × 103 × 9.81 × 760/1000
= 101.325 kN/m2 = 101.325 kPa
= 1.01325 bar
While the density of mercury is taken as 13.595 kg/m3 and acceleration because of gravity like 9.8066 m/s2