A gas is contained in a closed cylinder with a mobile piston at oneof its ends. For the following conditions indicate: (1) if dW= -pdV or not, and (2) if the process is reversible, quasistatic,or irreversible. Explain in each case why is one or another.
a) There is no pressure form the out over the piston and there is no friction between the piston and the cylinder's walls.
b) There is no external pressure and there is a small frictionbetween piston and cylinder's walls.
c) The piston is pulled outwards faster than the molecules's (ofthe gas) average velocity.
d) Friction adjusts in such a way that it permits the gas toexpand slowly.
e) There is not friction, but the external pressure adjusts so thatit permits the gas to expand slowly.