1. Chapter 7 Question 66: Many tongues have been injured by locking a piece of metal on a very cold day. Why would little harm result if one licked a piece of wood on the same very cold day? (0.75 pts)

2. Chapter 7 Question 70: Snowmaking machines used at ski areas blow a mixture of compressed air and water through a nozzle. The temperature of the mixture may initially be well above the freezing temperature of water, yet crystals of snow are formed as the mixture is ejected from the nozzle. Explain how this happens (0.75 pts)

3. Chapter 7 Question 84: Consider the solar energy that enters a florist's greenhouse and is absorbed by plants. Why is the energy that is reradiated by the plants of a much lower frequency than the solar energy? (0.5 pts)

3. Chapter 7 Question 120: Why can you drink a cup of boiling-hot tea atop a high mountain without any danger of burning your lips? What if you did this in a mine shaft below sea level? (0.5 pts)

4. Chapter 10 Question 72: What two physics mistakes occur in science-fiction movies that show, in outer space, a distant explosion that you see and hear at the same time. Hint: the explosion itself is not the mistake (0.5 pts)

5.Chapter 10 Question 86: A bat chirps as it flies toward a wall. Is the frequency of the echoed chirps it receives higher, lower, or the same as that of the emitted chirps? Explain. (0.75 pts)

6. Chapter 10 Question 92: How can a certain note sung by a singer cause a crystal glass to shatter? Be sure to explain your answer fully (0.5 pts)

7. Chapter 10 Question 96: When the frequency of sound is doubled, what change occurs in its speed, if any? What change occurs in its wave-length, if any? Explain your answers. (0.75 pts)