4B.1

[Kyle Rex 1K]

if work is a piston compressing the gas and the work is given as 300kJ (for example), when solving for delta U of the gas inside a close container using delta U=q+w, would w be positive or negative?

[Alicia Lin 2F]

It is positive because the force exerted is in the same direction as the displacement. And when work is done on the system, it is positive.

[Gurmukhi Bevli 4G]

It would be positive since work is being performed on the system.

[Leonardo Le Merle 1D]

Think about the energy of the gas; because a force is being exerted on it (W), that results in an increased pressure and energy (U) in that system - it might heat up as a result.

[Bryce Barbee]

In that equation, the Work is equal to Work(on the system). Therefore work would be positive because the system is being compressed by the piston.

[Abby Soriano 1J]

It's always a good idea to think of both work and heat from the perspective of the system. We know that endothermic reactions are categorized with a +delta H since they are taking in heat. With that same concept, we can think of positive work or heat as being applied to the system. If heat is added to the system q is positive. If work is being done to the system, w is positive.

[Betania Hernandez 2E]

It would be positive since work is being done on the system.