Question

Assuming the density of air to be 1.295 kg m^-3, find the fall in barometric height in mm of Hg at a height of 107 m above the sea level. Take density of mercury = 13.6 × 10³ kg m^-3.

Answer 1

Let h = 107 m be the height above sea level

∴ `P_h - P_(sea) = ρ_(air)  gh`

∴ `ρ_m gh_f - ρ_m gh_i = ρ_(air) gh`

∴ `ρ_m gΔh = ρ_(air)gh`

∴ `Δh = (ρ_(air) h)/ρ_m = (1.295 xx 107)/(13.6 xx 10^3)`

∴ Δh = 0.010 m of Hg

∴ Δh = 10 mm of Hg