1. The problem statement, all variables and given/known data From the beginning of chapter 21 Haliday, Resnick and Walker: `Suppose that you return to your chilly dwelling after snowshoeing through the woods on a cold winter day. Your first thought is to light a stove. But why, exactly, would you do that? Is it because the stove will increase the store of internal (thermal) energy of the air in the cabin, until eventually the air will have enough of that internal energy to keep you comfortable? As logical as this reasoning sounds, it is flawed, because the air's store of internal enrgy will not be changed by the stove. How can that be? And if it is so, why would you bother to light the stove?' 3. The attempt at a solution I'm confused by what HRW are saying here. My understanding is that the stove releases heat into the constant-volume environment which raises the internal energy according to the first law of thermodynamics [itex]dU = Q - PdV = Q[/itex]. Am I missing something here?