SAT Subject Physics Practice Question 275: Answer and Explanation
46. What does the second law of thermodynamics say should happen to an isolated, ordered system?
A. Heat will flow into the system.
B. Heat will flow out of the system.
C. Work will be done by the system.
D. Work will be done on the system.
E. The entropy within the system will increase.
Correct Answer: E
By definition of an isolated system, A, B, C, and D are all false. The second law of thermodynamics tells us that in this situation, an ordered system will become more disordered, moving toward a state of maximum entropy.