Assuming that air temperature remains constant at all altitudes and that the variation of g with altitude is negligible (a) show that the pressure P at an altitude h above sea level is given by p = p0 exp(Mgh/ RT ), where M is the molecular weight of the gas. (b) show that n = n0 exp(Mgh/ RT ) where n is the number of molecules per unit volume. (c) taking the average molecular weight of air to be 29 g, calculate the height at which the air pressure would be half the value at sea level.
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