-21. How many calories of heat are required to 

 raise the temperature of 1,500 grams of 

 water from 25° C to 85° C? 



1. 60 cal 



2. 1,500 cal 



3. 90,000 cal 



4. 127,500 cal 



-22. Which of the following pairs of change of 

 state processes will produce similar 

 results? 



1. Melting and fusion 



2. Freezing and condensation 



3. Melting and evaporation 



4. Condensation and evaporation 



In items 8-23 through 8-25, select from column 

 the type of latent heat defined by each state- 

 ment in column A. 



Statements 



B. Types of 



Latent Heat 



1. Sublimation 



-23. It is heat that is 



released when a sub- 

 stance changes from a 



liquid state to a solid 2. Vaporiza- 

 tion 

 -24. It is heat that is 



released when a sub- 3. Fusion 



stance changes from a 



vapor state to a liquid 4. Condensa- 

 tion 

 -25. It is heat that is 



absorbed when a substance 



changes from a liquid 



state to a vapor 



8-26. What is the meteorological term for the 

 process that results when a substance 

 changes directly from a solid to a vapor 

 or directly from a vapor to a solid? 



1. Fusion 



2. Sublimation 



3. Condensation 



4. Crystallization 



8-27. What term defines the process by which 

 water vapor turns to ice without first 

 becoming a liquid? 



1. Sublimation 



2. Fusion 



3. Condensation 



4. Crystallization 



Learning Objective: Identify the 

 characteristics of the adiabatic 

 process and the methods of heat 

 transfer, including the computa- 

 tion of air mass temperature 

 differences and lapse rates. 



8-28. What causes the temperature of a given 

 volume of air to rise if that volume of 

 air is compressed adiabatically? 



1. Heat is absorbed by the air mass 

 through exchange with the environment 



2. Additional heat is absorbed by the 

 air mass from the forces causing 

 compression 



3. Compression eliminates moisture, 

 thereby allowing the temperature to 

 rise 



4. Heat is generated by the work of 

 compression 



8-29. When is a lifted parcel of air considered 

 unstable? 



1. When it becomes less dense than the 

 surrounding air 



2. When it becomes denser than the 

 surrounding air 



3. When its density remains the same 

 as the surrounding air 



4. When it is forced up a mountain slope 



8-30. A mass of air that is unsaturated at a 



temperature of 75° F is starting to rise 

 from the earth's surface and to cool 

 adiabatically. If it becomes saturated 

 when its temperature falls to 53° F, how 

 high will it be when condensation occurs? 



1. 4,000 ft 



2. 9,636 ft 



3. 12,100 ft 



4. 13,636 ft 



8-31. A saturated mass of air having a tempera- 

 ture of 38° F is at 6,500 feet and is 

 forced over a 13,500-foot mountain. Con- 

 densation occurs from 6,500 to 13,500 

 feet and falls from the air during ascent. 

 What will be the approximate temperature 

 of this air mass at 6,500 feet as it 

 descends the other side of the mountain? 



1. 20.5° F 



2. 38.0° F 



3. 38.5° F 



4. 59.0° F 



^ In items 8-32 and 8-33 assume that a par- 

 cel of air having a temperature of 60° F 

 is at 3,500 feet and is forced over a 14,500-foot 

 mountain. Condensation occurs from 3,500 feet to 

 14,500 feet so that the parcel cools at the moist 

 adiabatic lapse rate and reaches a temperature of 

 approximately 27° F at the top of the mountain. 

 As the condensation has fallen out of the air 

 during the ascent, the parcel will heat at the 

 dry adiabatic lapse rate as it descends on the 

 other side of the mountain. 



8-32. What will be the adiabatic lapse rate of 

 cooling as the air rises? 



1. 2° F 



2. 3° F 



3. 4 1/2° F 



4. 5 1/2° F 



47 



