8. In the given figure, the volume at point \"D\" is 800 L and the pressure is 2
ID: 2252612 • Letter: 8
Question
8.
In the given figure, the volume at point "D" is 800 L and the pressure is 2 atm. The volume at "A" is 400 L and the pressure is 5 atm. What is the work (W) done at the system gives through one complete cycle above? What heat (H) is absorbed by the system in the above square cycle? Put the letter on the opprepriate blank. _______800000 J _______400000 J _______280000 J _______120000 J In the given figure, the volume at point "D" is 800 L and the pressure is 2 atm. The volume at "A" is 400 L and the pressure is 5 atm. What is the work done at the system gives through one complete cycle above? _______ - 60000 J _______ 0 J _______60000 J _______120000 JExplanation / Answer
a)
1 L = 0.001 m^3
1 atm = 101325 pa
also, Vc=Va and Vb=Vd
Pa=Pb and Pc=Pd
so,
W(dc) = -P*dV = -P(Vc-Vd) = -2*101325*(400*0.001-800*0.001) = 81060 J
W(ca) = 0 ..(Volume const.)
W(ab) = -P(Vb-Va) = -5*101325*(800*0.001-400*0.001) = -202650 J
W(bd) = 0 ..(Volume const.)
so,
Total work done = W = -202650+81060 = -121590 J
as,
U=0
Q=-W = 121590 J = 120000 J (approx.)
b)
Work done = 0