APPROACH TO THERMAL-EQUILIBRIUM IN A SYSTEM WITH ADIABATIC CONSTRAINTS

The problem of prediction of the equilibrium state in an isolated comp osite system with an adiabatic internal wall is a delicate problem, wh ose solution is easily seen to be not entirely determined in the frame of elementary thermodynamics. We show how this indeterminacy can be r emoved by introducing a suitable kinetic model, in which the influence of the finite velocity of the wall on the change of momentum of the g as molecules impinging on it plays a relevant role. An interesting fea ture of the entropy behavior of the system is discussed. (C) 1996 Amer ican Association of Physics Teachers.