The mean sea- level pressure of the atmosphere decreases by half at the altitude of ? A) 6 Km. B) 8 Km. C) 10 Km. D) 12 Km.

1 Answer
Oct 8, 2017



The atmospheric pressure depends by the weight of the air over us. air has a density of about #0,9 (kg)/m^3 # that decreases with altitude starting from about #1,2 (kg)/m^3 # at ground level to #0,6 (kg)/m^3# at about 6000 m). therefore an height of air of 6000 m wiht a m^2 of surface weighs about # P= d xx V xx g = 0,9(kg)/m^3 xx 6000 m^3 xx 10 m/s^2= 54000 N# that give on a surface of a m^2 a pressure of 54000 Pascal , about 0,5 atm.
1 atm is 101325 Pa