An ideal gas (degree of freemdom i = 5) is in a closed system like the given figure. Process (1) to (2) is isothermal. Process (2) to (3) is adiabatic. Process (3) to (4) is isobaric. Process (4) to (1) is isochoric.

At state (1): Pressure [tex]p_1=5*10^5 Pa[/tex], volume [tex]V_1=3*10^{-3} m^3[/tex].
At state (2): Volume [tex]V_2=3V_1[/tex].
At state (3): Pressure [tex]P_3=P_1/5[/tex].

Find:
a) The total of work A in each process. ([tex]A=A_{12}+A_{23}+A_{34}+A_{41}[/tex])
b) The total of positive heat energy Q+ and the total of negative heat energy Q- in each process.
c) The effeciency of the system. (η = -A / Q+)