ABSTRACT
This chapter explores some recallings of physics, especially to the notions of pressure, work, heat and temperature since they are recurrent in thermodynamics. Although the methods of classical thermodynamics are independent of any theory concerning the existence of atoms and of molecules, it is well-admitted that some kind of work, pressure and temperature are manifestations of the movements of these “particles”. Actually, a perfect gas is only a theoretical model. However, the behavior of a dilute gas tends to be that of a perfect gas. This is because, then, the average distance between the molecules is great with respect to the range of interactions due to the intermolecular forces. It is particularly interesting to study the notion of pressure from the microphysical standpoint, that is to say by considering that the pressure exerted on a surface is due to the collisions of the molecules of the gas with the latter.
