This problem is going to make me go crazy... 4. In the figure below, an ideal gas is slowly compressed at a constant pressure of 2.0 atm from 10.0 L to 2.0 L. This process is represented as the path B to D. In this process, some heat flows out and the temperature drops. If the heat lost from the gas in the process BD is 3.53E3 J, what is the change in internal energy of the gas? Ok... all i have so far is since the pressure remains constant, it's an isobaric process. Therefore i have to calculate work. W=(2E5)(.01-.002) W=1600 J Now is it positive or negative??? Then i know next step is the change in internal energy U=Q-W Since the heat is lost from the gas is it negative 3.53E3??? U=(3.53E3)-(-1600) Now i do not get the right answer... someone please explain why??? thanks.