## Work ( regarding internal energy)

$\Delta U=q+w$

JoseMAvila15
Posts: 14
Joined: Fri Sep 25, 2015 3:00 am

### Work ( regarding internal energy)

EXAMPLE: The internal energy of a system decreased by 1763kj after preforming 1357kj of work. Was heat transfered to or from the system?

My question is how do we know when the work is negative or positive, what do we look at to tell this?

JaeHoCho1B
Posts: 16
Joined: Sat Jul 09, 2016 3:00 am

### Re: Work ( regarding internal energy)

Work is negative when it's "done by the system" and not "done by its surroundings."