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 x 10^3 kg m-3

density of air = 1.295 kg m^-3

h = 107 m

As we know,

decrease in pressure = h ρ g — (i) 

= (107) × (1.295) × (g)

Let, decrease in mercury height = H

∴ decrease in barometric height = (H) × (13.6 x 10³) × (g) — (ii)

Equating 1 and 2 we get,

(H) × (13.6 × 10³) × (g) = (107) × (1.295) × (g)

⇒ 13600 H = 138.565

⇒ H = 138.565/13600 = 0.0101 m of Hg

Therefore, fall in barometric height = 10 mm of Hg.