## 8.7

$\Delta U=q+w$

veneziaramirez 3I
Posts: 57
Joined: Fri Sep 29, 2017 7:07 am

### 8.7

Why is 982 delta U? Wouldn’t it be 982J- 492J? Aren’t work and delta U the same thing as according to 8.3 c?

Sophie Krylova 2J
Posts: 59
Joined: Fri Sep 29, 2017 7:06 am

### Re: 8.7

I haven't looked at the problem specifically, but dU is not just work. dU = w + q (q is heat)

Nancy Dinh 2J
Posts: 59
Joined: Fri Sep 29, 2017 7:07 am

### Re: 8.7

veneziaramirez 3I wrote:Why is 982 delta U? Wouldn’t it be 982J- 492J? Aren’t work and delta U the same thing as according to 8.3 c?

The internal energy of a system is delta U, so delta U is given at 982 J. The equation is delta U = w + q, where heat is given at +492 J, so 982J - 492J will give you how much work is done.

Delta U and work are only equal when q=0 where no heat is absorbed or released. In Exercise 8.3, there is no change in temperature.