A thermodynamic system is taken from an original state D to an intermediate state E by the linear process shown in (figure)

Its volume is then reduced to the original value from E to D via F by an isobaric process. Calculate the total work done by the gas from D to E to F to D.

Explanation

As is clear from (figure)
Change in pressure, `dP=DF= 5.0-2.0= 3.0 atm = 3.0xx10^(5)Nm^(-2)`
Change in volume, `dV= EF= 600-300= 300 c c= 300xx10^(-6)m^(3)`
Work done by the gas from D to E to F `= area of DeltaDEF`
`W=1/2xxEFxxDF= 1/2xx(300xx10^(-6))xx(3.0xx10^(5))= 45J`