question_answer

In the upper part of the atmosphere the kinetic temperature of air is of the order of\[\mathbf{1000}\text{ }\mathbf{K}\], event then one feels severe cold there. Why?

Answer:

                As we go up in the atmosphere, the number of air molecules per unit volume decreases. The quantity of heat per unit volume or the heat density is low. But the translational kinetic energy per molecule is quite large. As the kinetic temperature is the measure of translational kinetic energy, so the kinetic temperature is quite high in the upper atmosphere but one feels severe cold there due to low heat density.