A barometer having a cross - sectional area of 1.00 cm2 at sea level measures a pressure of 76.0 cm of Hg. The pressure exerted by this column of mercury is equal to the pressure exerted by the air on 1 cm2 of the earth's surface. The total mass of earth's atmosphere is___. (Average radius of earth is p km and density of mercury is 13.6 g/ml)
Pressure=ForceArea=mass×accelerationarea
hdg=m×g4πr2⇒m=hd4πr2
⇒m=0.76×13.6×103×4π⟮P×103⟯2
= 4πP2×0.76×13.6×109 kg