I'm a bit confused about the cgl. If I pump 3 liters of air into a 3 liter cylinder already filled with 3 liters of air, what will be the temperature rise? Assuming an initial temperature of 300'K. It seems like from practice, the temperature goes up. Is the temperature rise due strictly to the friction in the pump? Should I break this down into two separate problems? the physics of the pump and that of the tank?