work = 0

[Samuel G Rivera - Discussion 4I]

Why does work equal 0 when, for example, a system pushes a piston out within a vacuum? If the piston is moving wasn't work done to move it?

[Diana_Diep2I]

I think it is because the system isn't pushing/expanding any pressure from the outside

[CynthiaLy4F]

The work done under a vacuum is equal to 0 because the external pressure is equal to 0. This is also known as free expansion where there is no opposing force that allows for work to be done.

[Daria Azizad 1K]

In a vacuum, there is nothing to push against, therefore no work is performed.

[Osvaldo SanchezF -1H]

There is free expansion occurring in the system which is also known as vacuum and there for no work is done and for some problems it will be combined with an isobaric system so if deltaU and work is 0 then q is 0. This way you apply all concepts and how they all relate to each other.

[WesleyWu_1C]

The work would be zero because in this vacuum the external pressure is zero. The system is not using any energy to push the piston up.

[Tahlia Mullins]

In a vacuum, the external pressure is equal to 0, so during free expansion, work is also equal to 0.

[Natalie Benitez 1E]

Under what conditions does work equal zero?

[Wilson 2E]

If a system is isochoric (constant volume), no work will be done since w = p*deltaV, and since there is no change in volume the w = 0.

[faithkim1L]

I believe this is because there is no external pressure pushing the piston in, so there is free expansion (the system can do work freely).

[Ashley Nguyen 2L]

Because work is equal to Pexternal*deltaV, in a vacuum there is no external pressure, making work = 0. The system is not doing work on the surroundings because the surroundings are not pushing back.

[J Medina 2I]

Pressure inside a vacuum is zero so when using the equation w = - P ex * delta V, the work done by a system is also equal to zero.

[John Liang 2I]

according to the equation w=-Pex*delta V, if external pressure is 0 (as in a vaccuum), then w equals 0. hope this helps!

[Helen Struble 2F]

In order for work to be done, it has to be done on something—work measures the transfer of energy. In a vacuum, there is no gas to transfer energy to, so no work is done.

[Daria MacAuslan 1H]

when looking at work in an irreversible expansion, it is equal to external pressure times change in volume. In a vacuum, there is no external pressure so there is no work done