Thermodynamic work

Thermodynamic Work:

Work is said to be done if the sole effect on the things can be reduced in raising of weight (weight may not be raised). for example imagine a cylinder with piston of weight 'W', when heat is transferred into the cylinder the pressure inside the cylinder increases there by lifting the piston to some height where heat energy is transformed to work.

Sign convention:

• Work done by the system is positive.
• Work done on the system is negative.

Remember:

• Work is not a property.
• Work is inexact differential.

How thermodynamic work is calculated ?

For Closed system:

For  closed system  the net amount of work done is equal to area under the curve of path between points A and B. The closed system work is obtained by plotting it on volume axis.
For Open system:

For  open system  the net amount of work done is equal to area towards the left side of the curve of path AB and vertical axis of P-V diagram. The open system work is obtained by plotting it on  pressure axis.