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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.
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Solution
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
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