ADIABATIC WORK

Apparatus

• Insulated cylinder with movable piston and two side chambers, both initially evacuated, also with stirrer operated by electric motor

Problem

• Compare the work done in three different processes, involving both quasi-equilibrium and non-equilibrium processes

Process a. Air is initially at State O. Move piston to compress air until State A is reached.Lock piston in place.Open the valve leading to chamber A.Unlock piston.Move piston until State C’ is reached

Process b. Air is initially at State OAir Move piston to compress air until State B is reached.Lock piston in place.Open the valve leading to chamber B.Unlock piston.Move piston until State C’ is reached

Process c. Air is initially at State OPiston remains fixed throughout process.Run stirrer until system reaches State C’

ENERGY CHANGE DEPENDS ONEND STATES ONLY

WORK DEPENDS ON END STATES

ANDHOW PROCESS IS CARRIED OUT

(PROCESS PATH)

SINCE UC’ - UO = OQC’ - OWC’

IN GENERAL,