## Delta U

$\Delta U=q+w$

Abigail Menchaca_1H
Posts: 104
Joined: Sat Sep 07, 2019 12:19 am

### Delta U

When calculating the internal energy of the system how do you know when to change the sign of q/w?

DarrenKim_1H
Posts: 123
Joined: Fri Sep 20, 2019 12:17 am
Been upvoted: 1 time

### Re: Delta U

Multiple factors indicate whether to change the sign. For example if work is done on the system it is positive and if it is done by then it is negative

Diana A 2L
Posts: 106
Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

### Re: Delta U

Also, if heat is released, q is negative, and if it's absorbed, q is positive. Then you use the delta U= q+w equation to determine if overall internal energy is positive or negative.

Ayushi2011
Posts: 101
Joined: Wed Feb 27, 2019 12:17 am

### Re: Delta U

Depends on whether work is done or work is being done on the system.

Owen-Koetters-4I
Posts: 50
Joined: Fri Sep 28, 2018 12:16 am

### Re: Delta U

you examine if work is done on or by the system