Question

When a gas follows path 123 on the PV diagram in the figure below, 419 J of energy flows into the system by heat and −171 J of work is done on the gas.

A rectangular path is plotted on a PV diagram that has a horizontal axis labeled V, and a vertical axis labeled P. The vertices of the rectangle, starting from the bottom-left corner and continuing clockwise, are labeled in the following order: 1, 2, 3, 4. The area within the rectangle is shaded.

(a) What is the change in the internal energy of the system?
(b) How much energy Q flows into the system if the gas follows path 143? The work done on the gas along this path is −63.0 J.
(c) What net work would be done on the system if the system followed path 12341?
(d) What net work would be done on the system if the system followed path 14321?
(e) What is the change in internal energy of the system in the processes described in parts (c) and (d)?

Answer 1

au ot > V change in Internal Energy - heat given to system – work done by gas AU = 9 - wogas AU = 419 - (+171) - +171 AU = 2485 same as it is both AU will be independent AU = 248 = 9 - 63 - = 311 J

– along poth 12341 Closed both so AU=0 Q, +02-W,-W2 = 0 Onet - what 1 Onet - 0123 - 034e} 419-311 = 1085 » 7 work done by system = 1085 work done on system = -108 J W 14321 = – W12341 = 1085 Both are closed both so 40=0