When a student cleans their dorm room, the entropy of the system must decrease. How is this NOT a violation of the second law of thermodynamics?
The entropy of the room decreases, but because energy is absorbed, the total entropy increases.
Energy is transferred from the universe to the room, increasing the entropy of the universe.
Energy is expended, so the entropy of the universe continues to increase.
The entropy of the dorm room decreases, but the internal entropy of the objects increases.