## negative vs. positive internal energy

$w=-P\Delta V$
and
$w=-\int_{V_{1}}^{V_{2}}PdV=-nRTln\frac{V_{2}}{V_{1}}$

haleyervin7
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### negative vs. positive internal energy

What is happening physically in a system when the change of internal energy of a system is negative vs. positive?

Ibrahim Malik 1H
Posts: 65
Joined: Fri Sep 28, 2018 12:27 am
Been upvoted: 1 time

### Re: negative vs. positive internal energy

When the change in internal energy of a system is negative, it means work is being done on the environment. When the change in internal energy of a system is positive, it means work is being done on the system from the environment.

904914909
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am

### Re: negative vs. positive internal energy

When U is negative, that means the net energy is out of the system or the system is doing work on the surrounding. When U is positive, that means net energy is into the system or the surroundings are doing work on the system.