## W=-P(deltaV) sign

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

Jack Papciak 2F
Posts: 31
Joined: Fri Sep 29, 2017 7:06 am

### W=-P(deltaV) sign

Why is there a negative in front of V? I know it has something to do with work done on the system/surroundings but I am confused which sign goes with what.
Last edited by Jack Papciak 2F on Tue Feb 13, 2018 8:47 pm, edited 1 time in total.

Emily Glaser 1F
Posts: 156
Joined: Thu Jul 27, 2017 3:01 am

### Re: W=-P(deltaT) sign

p delta V?

Jack Papciak 2F
Posts: 31
Joined: Fri Sep 29, 2017 7:06 am

### Re: W=-P(deltaT) sign

Sorry it should be a V not a T

ZoeHahn1J
Posts: 63
Joined: Sat Jul 22, 2017 3:01 am
Been upvoted: 1 time

### Re: W=-P(deltaV) sign

If there is an increase in V, work is being done by the system, so w will be negative. When work is being done on the system, there will be a decrease in V, so work will be positive.