Timeline for What does it mean for work to be done ON a system?
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Sep 25 at 9:02 | comment | added | Sneftel | @Anna The phrase does not have a rigidly formal definition, but I think most would say that a state change is necessary but not really sufficient. If you flip a big toggle switch which allows a volume of gas to expand adiabatically, you did work to flip the switch, and the system changed, but it wasn't really work being done "on" the system. I would say that adding (or, arguably, removing) energy is also necessary. | |
| Sep 25 at 7:39 | comment | added | Anna | I think I may have a way of thinking about it that makes sense to me. Suppose we do work somewhere in the universe. If this work happens to also change the the state parameters of a system of interest, then work was done ON the system. If none of its state parameters were changed, no work was done on it. Is this a valid way of thinking about it? | |
| Sep 24 at 22:59 | comment | added | hft | @Anna The piston is assumed to be: (1) a rigid body; (2) freely movable so there is no friction of the piston in the cylinder; and (3) movable in such a way that its acceleration can be ignored. Thus, the force of your hand pushing on the piston is the same as the force of the piston pushing on the gas. The gas can be considered a compressible fluid that is pushed on by the piston and thereby compressed. | |
| Sep 24 at 21:31 | comment | added | Anna | Thank you for your answer. I think the crux of my issue is the following: I understand that we are imparting a force on the piston, but how is this equivalent to applying a force on the gas, i.e, our system? | |
| Sep 24 at 21:14 | history | edited | hft | CC BY-SA 4.0 | added 542 characters in body |
| Sep 24 at 21:01 | history | answered | hft | CC BY-SA 4.0 |