Ideal Gas Cycle: N2 Undergoing abcd w/ Varying Pressures

[Luis2101]

Two moles of N2 gas undergo the cycle abcd. The pressure of the gas in each state is
pa = pd = 5500 Pa;

pb = pc = 1500 Pa.


Note that 5500 Pa > 1500 Pa. The volume of the gas in each state is
Va = Vb = 1.80m^3 ;

Vc = Vd = 8.70m^3.

Note that 8.70 m^3 > 1.80 m^3. The gas may be treated as ideal.

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Part A asks: Find the magnitude of the total work done on (or by) the gas in the complete cycle.

I tried to approach the problem in the following manner and got an incorrect answer for Part A.

I treated the process from A->B, as well as from C->D as Isochoric since Volume is constant, and said no work was done.

I then calculated the work from B->C:
Using: W = p(deltaV) = 1500 (8.7-1.8) = 10,350J.

I said this was the total work done, but it's not...
Any help would be greatly appreciated.

-Luis

 

[Luis2101]

Nevermind. I found a link in the archives and figured it out from there.
Here it is if anyone needs it:
https://www.physicsforums.com/showthread.php?t=55853