# Work done by cyclic process (thermodynamics)

## Homework Statement

http://s9.postimage.org/5iw5rixyl/image.jpg
(sorry doesn't let me embed)

## Homework Equations

P1V1=P2V2
and
PV=nRT

I know that Work done by gas from a --> b = (nRT)*Integral(V2/V1)
My question is do i use PV=nRT to find N? and if T is constant (isothermal) what do I plug in for T when evaluating work?

Using PV=nRT I got n= 14.440 when T=constant (1), is this correct?

I appreciate all of your help.

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## Answers and Replies

bump. i really need help.

n is constant so you shouldn't need to worry about it.
(PV)/(nRT)=1 for both "a" and "b" so we can set them equal since they both equal 1.
=> P_f*V_f = P_i*V_i
Now you can solve for P_f since everything else is given.
At this point you can integrate from each initial to final (remember to set your integrals limits in the correct order). The total work is the sum of the individual work done on/by the system.