Work

[Chaleah Duran]

How can one tell when work is on a system and when it is by a system?

[Nathan Tran 1B]

If the work value is negative the work is being done by the system and if the work value is positive the work is being done onto the system I believe. I think it is important to think about perspective of surrounding vs system. If we are looking at work through the perspective of the surrounding then a positive work value of the surrounding would mean it is gaining energy from the system and thus the work value of the system is negative. Hopes this helps.

[A 3F]

When work is done by the system, the system is losing energy, volume increases, and work would be negative. When work is done on the system, the system is absorbing energy, volume decreases, and work would be positive.

[Joan Moci 1J]

If the work is negative, then the work is by the system and the system is losing internal energy. This means that the volume of the system is increasing, the system is expanding. If the work positive, the work is on the system and the system is gaining internal energy. This means that the volume of the system is decreasing and the system is being compressed.

[Coraly De Leon]

Hello !
We will know this difference because...
the internal energy of the system will increase when work is done in the sytem whereas, work done by the system will cause a decrease in internal energy.

[305561744]

What is the relationship between work and heat?

[Desiree Eshraghi 3A]

Work IN the system INcreases INternal energy. Work by the system decreases internal energy as a default.

[Isha Tripathi 2F]

If a work is being done on a system we would expect to have an increase in energy. If work is being done by the system the internal energy decreases.

[Mekenna Faulkner]

When work is negative work is being done by the system since internal energy is decreasing and energy is being lost to the surroundings, usually increasing volume. Positive work is work being done on the system since it is gaining energy. Work refers to the effect on the system.

[Sophia Manos 1F]

Hi! When work is being done by a system the system is losing energy, so the work would end up being negative. You can think of this as internal energy of the system increasing when work is being done IN the system, while work being done BY the system causes the energy to decrease. Hope this helps!

[Chaleah Duran]

This helps thank you!

[Ashley Presnell 1C]

When work is being done on the system, the value of work would be positive, indicating the system is gaining energy. However, when work is being done BY the system, work is negative as it is losing energy, such as when the volume expands, requiring work by the system to do so.

[trevina_brown_2A]

The internal energy of the system will increase when work is done in the system and work done by the system will cause a decrease in internal energy.

[LukeYing_3H]

The internal energy increases when work is done on a system and decreases when the system does work on something else.

[Madison Rhynhart 3H]

When work is being done by the system this would cause the system as a whole to lose energy therefore work or w would be negative. However, if work is being done to a system, then it would be absorbing or taking in energy and thus work or w is positive.

[riddhiparikh]

If system volume expands against a force, work is done by the system. If system volume contracts under a force, work is done on the system. If energy enters the system, its sign is positive. If energy leaves the system, its sign is negative. If work is done on the system its sign is positive aka energy entering the system. and vice versa.

[PatrickV]

When the work value is negative the work is being done by the system. When the work value is positive, the work is being done to the system. Another way to tell is if the system volume expands against a force, work is done by the system. If system volume contracts under a force, work is done on the system.

[Sarthika Chimmula 3H]

When the work is negative it is being done by the system. When the work is positive it is being done on the system.

[705925790]

When using the work function for constant temperature, why is the equation derived from an integral of the gas law? I am just wondering for conceptual reasons.

[Jonathan Choe 3D]

When the work is negative it is being done by the system. When the work is positive it is being done on the system.

Work is done by the system when it is negative, and work is done on the system when it is positive.

[Nala Son 3B]

When work is done in a system, its internal energy increases as it is taking in energy. When work is done by the system, its internal energy decreases since it is expending energy to do the work.

[Jeff Balian 2D]

The equation w = nRT ln(V2 / V1) is the derived form of w = - Pex dV. The first equation calculated the work from an isothermic (constant temp) reversible expansion of a gas from V 1 to V 2.