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Work

Posted: Thu Feb 07, 2019 12:53 pm
by Ricky Ma DIS 4E
When the work of a system on the atmosphere is positive, does that mean that work is being done on it instead? What does positive work mean conceptually.

Re: Work

Posted: Thu Feb 07, 2019 1:15 pm
by Tyra Nguyen 4H
When the work of a system is positive, it means that the system is doing work. This can be seen as the gas in a container expanding, pushing a piston. The system is expanding, thus is doing work.

Conceptually, positive work means that work is being done by a system.

Re: Work

Posted: Thu Feb 07, 2019 1:24 pm
by mbaker4E
When the work of the system on the atmosphere is positive, that means work is done by the system, and so the equation would look like delta U = Q - W. When the work of the atmosphere or environment on the system is positive, it means work is being done on the system, which would correlate with the equation delta U = Q + W.

Re: Work

Posted: Thu Feb 07, 2019 1:58 pm
by Ricky Ma DIS 4E
Doesnt negative work mean that the system is losing energy from work? if p=1 atm but there is an increase in volume, the equation would be negative meaning system did work of expansion.

Re: Work

Posted: Thu Feb 07, 2019 2:07 pm
by isarose0
When work is positive, the surroundings are doing work on the system, ex: compression of piston, when work is negative, the system is doing work on the surroundings, ex: expansion of piston.