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Posted: Thu Jan 31, 2019 8:31 pm
How can you determine whether work was done by or on a system? Thank you.
Posted: Thu Jan 31, 2019 8:34 pm
If energy leaves a system, the system does work on its surroundings. If energy enters a system, work is done on the system.
Posted: Thu Jan 31, 2019 9:41 pm
When work is done on a system, w is positive. When work is done by a system, w is negative.
Posted: Fri Feb 01, 2019 1:22 am
Personally, what helps me the most is by looking at the keywords the problem is giving me. For example, if I see "work being done", I automatically assume it is positive because there is energy being entered on a system.