Question

A thermodynamic system is taken from an original state to an intermediate state by the linear process shown in Its volume is then reduced to the original value from E to F by an isobaric process. Calculate the total work done by the gas from D to E to F

Answer 1

Given, the pressure and volume at point F are 300 N/ m 2 and 2  m 3 , at point D are 600 N/ m 2 and 2  m 3 while at point E are 300 N/ m 2 and 5  m 3 .

The total work done by the gas from state D to E to F is the area of the graph subtended by the points. Hence, work done by gas is the area of ΔDEF.

Let W be the work done by the gas, then

W= 1 2 ( FE )( DF )

Substitute the values in the above expression.

W= 1 2 ×( 600−300 )×( 5−2 ) =450 J

Hence, the total work done by the gas is 450 J.