9. Which physical law underlies the first law of thermodynamics? a. conservation of matter b. increase in entropy C. conservation of energy d. conservation of work 10. What happens to the entropy of a bucket of water as it is cooled down (but not frozen)? a. It increases. b. It decreases. c. It stays the same. 11. What happens to the entropy of a cube of ice as it is melted? a. It increases, b. It decreases. c. It stays the same. A T=600K 1000 J 250 J a. A b. B a. A b. B 650 J Heat Engine Useful Work c. C d. A and B e. A and C B T = 600K 1000 J 600 J 400 Heat Engine Useful Work T-600K 1000 J OJ T=300K T = 300K T = 300K 12. Which of the heat engine designs above violates the first law of thermodynamics? 1000 J Heat Engine Useful Work c. C d. A and B e. A and C 13. Which of the heat engine designs above violates the second law of thermodynamics?