The escape speed from the Earth is about 11 000 m/s (Section 7.5). Assume that for a given type of gas to eventually escape the Earth’s atmosphere, its average molecular speed must be about of the escape speed.
(a) Which gas would be more likely to escape the Earth: (1) oxygen, (2) nitrogen, or (3) helium?
(b) Assuming a temperature of – 40 oF in the upper atmosphere, deter-mine the rms speed of a molecule of oxygen. Is it enough to escape the Earth? (Data: The mass of an oxygen molecule is 5.34 x 10-26 kg, that of a nitrogen molecule is 4.68 x 10-26 kg, and that of a helium molecule is 6.68 x 10-27 kg.