Two identical metal blocks, A at 350 K and B at 300 K
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Thermodynamics · Thermodynamics
Problem
Two identical metal blocks, A at 350 K and B at 300 K, are placed in thermal contact inside a perfectly insulated container and allowed to reach equilibrium. Which of the following best explains why energy flows from block A to block B?
(a) The process minimizes the total internal energy of the isolated system by allowing energy to concentrate in the cooler block.
(b) Greater thermal pressure in the hotter block pushes energy into the cooler block until the thermal pressures equalize.
(c) The process increases the total entropy of the isolated system by allowing energy to spread more uniformly.
(d) Total entropy of an isolated system must remain constant, so any entropy gained by block B must be balanced by an equal loss from block A.