## 8.47

$\Delta U=q+w$

Ammarah 2H
Posts: 30
Joined: Fri Sep 29, 2017 7:06 am

### 8.47

How do you know that the work is a positive value for #47?

Kyle Sheu 1C
Posts: 87
Joined: Fri Jun 23, 2017 11:39 am

### Re: 8.47

When work is done on the system, energy is being input, so we can think about it as a positive change in the system's energy