Question

At sea level , the atmospheric pressure is 76 cm of Hg . If air pressure falls by 10mm of Hg per 120m of ascent, what is the hight of a hill where the barometer reads 70 cm of Hg . State the assumption made by you.

Assumption: atmospheric pressure falls linearly with ascent.

Answer 1

for 10 mm of Hg pressure fall, ascent=120m
10mm =1cm
for 1cm of Hg pressure fall, ascent=120 m
as per the assumption atmospheric pressure falls linearly with ascent
hence for every cm of pressure fall the ascent is 120 m
At the hill stated in the question 76-70=6 cm of Hg
so the height =6*120=720 m