Hi to all! recently I been doing alot of thermodynamics in University, however I have a huge problem. Because it is my first semester I have to take physics class for freshmen, however I also take at the same time physics for year 2 Uni students. (This is cuz I can, cuz I am already a Sound Engineer.) anywho........ does anynody knows what the hell with this? Physicist Say: U=Q+W (When a system is expanded the gas does work so it looses Q therefore is negative) Engineers Say: U=Q-W (When a system is expanded the gas does work on the outside so therefore is positive) The problem is what the hell! cuz i'm taking physics for freshman they mixed engineers with physics and now i'm confused cuz i bothered to learn for physics cuz i want to be a physicist, and now i'm getting problems wrong because of this.........> So i want to check am I right on the statements I made above? Thanks!