alright, so I'm reviewing for a test I have on monday, and I was given a study guide which we must answer in order to get ready for the test. Now I just breeze through this stuff like its nothing, but I've found on discrepency. I even looked up the question online and i got 2 completely different answers, so, maybe someone here can guide me in the right direction, here it is.(adsbygoogle = window.adsbygoogle || []).push({});

A thermodynamic system undergoes a process in which its internal energy decreases by 500 J. If at the same time, 220 J of work is done on the system, find the heat transferred to or from the system.

its a simple dU = Q + W , but one place i found it ='s -720 [-500J - 220J] and the other I found it equaled -280 [-500J + 220J]. Any help is appreciated

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Thermodynamics and internal energy stuck

**Physics Forums | Science Articles, Homework Help, Discussion**