1. The problem statement, all variables and given/known data In a cylinder of an automobile engine, immediately after combustion the gas is confined to a volume of 50.0 cm3 and has an initial pressure of 3.00x106 Pa. The piston moves outward to a final volume of 300 cm3, and the gas expands without energy transfer by heat. (a) What is the final pressure of the gas? (b) How much work is done by the gas in expanding? 2. Relevant equations For this problem, assume the gas in the engine is diatomic with γ = 1.40 3. The attempt at a solution I have already solved part (a) of this problem, which is 2.44x106 Pa, but I am having a lot of trouble with part (b). I have found the equation W = -∫VfViPdv, but don't know exactly what to do with that. I know pressure is not a constant, so it can't be brought out of the integral. I'm really not sure where I should even start with this one.