A system is changed from state A to state B, increasing its internal energy by 4 x 104 J while 6 x 104 J of heat is added. The system is returned to state A while 3 x 104 J of heat is taken away. (U=Q-W)
a. Obtain the work done by the system as its state is changed from A to B.
b. Obtain the work done in changing from B to A.
c. Obtain the net work done.