pressure scale height we derived plane-parallel hydrostatic balance in class for an isothermal atmosphere. now let's see what it tells us. recall that the earth has mass m = 6 × 1024 kg and radius r 6378 km its atmosphere is made up of molecular nitrogen and oxygen, so that the average mass of a particle in the atmosphere is 30 proton masses (mp 1.66 x 10-27 kg) (a) presuming room temperature (300 k), calculate the scale height at sea level (b) how does it compare to the earth's radius? (c) the pressure at sea level is p 105 j m-3. calculate the mass column, of the atmosphere. y, (d) how deep would you have to go in t doubled from that he ocean so that the pressure is at sea level?