Conceptual Physics Mod #21 Textbook Answers

Chapter 23, Pages 463 – 464: #2-20 even
2. What is evaporation, and why is it also a cooling process?
4. What is condensation, and why is it also a warming process?
6. Which usually contains more water vapor-warm air or cool air?
8. How can you tell if the rate of evaporation equals the rate of condensations?
10. What is the difference between evaporation and boiling?
12. Why is a pressure cooker even more useful when cooking food in the mountains than when cooking at sea level?
14. How can water be made to both boil and freeze at the same time?
16.a. How many calories are needed to raise the temperature of 1 gram of water by 1degree C?
b. How many calories are needed to melt 1 gram of ice at 0 degree C?
c. How many calories are needed to vaporize 1 gram of boiling water at 100 degree C?
18. What is the effect of rapid evaporation on the temperature of water?
20. Why is it important that a finger be wet before it is touched to a hot clothes iron?