Warm air is contained in a piston-cylinder assembly cools slowly from volume of 0.003 m^3 to 0.002 m^3. During the process a spring exerts a force that varies linearly from an initial value of 900 N to final value of 0. Patm = 100 kPa and the area of the piston face is 0.018 m^2. Or, V1 = 0.003 m^3 V2 = 0.002 m^3 F1 = 900 N F2 = 0 Patm = 100 kPa I'm not exactly sure where to start here. Can someone help me figure out what formula to use?