Irreversible and reversible expansion

[Vikram Senthil]

Hi, can someone explain how work of expansion is affected by the direction of the expansion?

[Fardean_Khajehmiraki_3l]

if the system is compressed, work is being done on the system meaning that the sign of work is positive, whereas if the system expands, the system itself is doing work so the sign of work is negative.

[Diana Alvarez 3A]

If the system is doing work itself by pushing out the piston, the work is negative. if the piston is being moved by an external force, the work is positive. All of this is in the perspective of the system.