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### Work done vs work on system

Posted: Tue Feb 12, 2019 10:04 pm
I know that there can either be work done on the system or work done by the system but I can't remember which one is positive and which one is negative when being calculated?

### Re: Work done vs work on system

Posted: Tue Feb 12, 2019 10:16 pm
When work is done by a system, work is negative. This is because work is essentially in energy units (J or kJ), and work is how a system loses energy. Therefore, if a system does work, the system is losing that energy it had.

When work is done on a system, that energy released is absorbed by the system. Hence, work is positive when it is done on the system.

### Re: Work done vs work on system

Posted: Sun Feb 17, 2019 3:30 pm
I like to think of it in terms of the system. If you're the system and you're doing work, you lose energy (negative w). If your system is doing work it's losing energy. If work is being done on the system its gaining energy.

### Re: Work done vs work on system

Posted: Sun Feb 17, 2019 3:37 pm
When work is being done on the system, w is positive, and when work is being done by the system w is negative.

### Re: Work done vs work on system

Posted: Sun Feb 17, 2019 4:08 pm
When it says that there is work done onto a system, the value is positive. When it says there is work done by the system, the value is negative for the system.

### Re: Work done vs work on system

Posted: Sun Feb 17, 2019 4:52 pm
"on" the system its positive and "by" the system its negative

### Re: Work done vs work on system

Posted: Sun Feb 17, 2019 5:37 pm
When work is done on a system, or by the environment, energy is added to the system and is thus positive. when work is being done by the system, energy is being used by the system and is thus negative.

### Re: Work done vs work on system

Posted: Sun Feb 17, 2019 6:31 pm
work done by system is negative. its putting energy into something else aka its losing energy. and vice versa

### Re: Work done vs work on system

Posted: Sun Feb 17, 2019 10:13 pm
When work is done on the system, work is positive.
When the system does work, work is negative.

### Re: Work done vs work on system

Posted: Tue Feb 19, 2019 9:17 pm
Think about it in terms of yourself.
if you're doing a workout, you lose energy.
But if someone else is doing it, you're positive energy.

### Re: Work done vs work on system

Posted: Wed Feb 20, 2019 9:20 am
When work is done BY the system w is negative and when work is done ON the system w is positive.

### Re: Work done vs work on system

Posted: Sat Mar 09, 2019 8:38 am
When work is done on a system, the work has a positive value. When work is done by a system, the work has a negative value.

### Re: Work done vs work on system

Posted: Mon Mar 11, 2019 3:54 pm
When the system is doing work it loses energy which makes it negative, while if the system has work done on it it gains energy and its a positive value.

### Re: Work done vs work on system

Posted: Mon Mar 11, 2019 8:07 pm
work done by the system is negative, work done on the system is positive

### Re: Work done vs work on system

Posted: Sun Mar 17, 2019 4:53 am
When work is being done ON the system, work is positive. When work is being done BY the system, work is negative since it is losing energy.

### Re: Work done vs work on system

Posted: Sun Mar 17, 2019 10:53 am
I believe the way we've been doing in class is work done by the system is negative and work done on a system is positive.

### Re: Work done vs work on system

Posted: Sun Mar 17, 2019 2:41 pm
Work done on the system is positive while work done by the system is negative

### Re: Work done vs work on system

Posted: Sun Mar 17, 2019 2:54 pm
Work done by the system results in a loss of energy from the system. This means that the internal energy is decreasing due to work. As a result, work is negative. Work being done on the system by outside forces means that energy is being inputted into the system. This makes the work positive.

### Re: Work done vs work on system

Posted: Sun Mar 17, 2019 10:15 pm
work being done on the system is positive while work being done by the system is negative.