1. The problem statement, all variables and given/known data The net work done on a certain gas is 55J, and the net heat flow into the gas is -23J. What is the net work done by the gas? 2. Relevant equations U = q + w 3. The attempt at a solution This problem seems very conceptual so I didn't use the formula above. I just deduced from this question that if the work done on a gas is 55J, then the work done by the gas is -55J. This is the correct answer but I got thrown off by the -23 J of net heat flow. What does this -23 really mean if the work done by the gas (-55J) is conserved?