7-38. A dekaineter is equivalent to approxi- 

 mately how many feet? 



1. 3.28 ft 



2. 3.93 ft 



3. 32.8 ft 



4. 39.3 ft 



7-39. How many inches are there in 2.5 meters? 



1. 0.98425 in. 



2. 9.84250 in. 



3. 98.42500 in. 



4. 984.25000 in. 



7-40. Approximately how many inches are there 

 in 25 centimeters? 



7-41. 



7-42. 



7-43. 



1. 



0, 



,984 



in 



2. 



9, 



,840 



in 



3. 



98, 



.400 



in 



4. 



984, 



,000 



in 



A cube whose volume is 1,000 cubic centi- 

 meters is referred to as a 



1. cubic liter 



2. liter 



3. cubic meter 



4. centiliter 



The force that applies acceleration to a 

 mass is measured in 



1. feet per second 



2. dynes 



3. meters per second 



4. ergs 



Approximately how many kilograms are the 

 equivalent of 24 pounds? 



1. 0.996 kg 



2. 11.000 kg 



3. 19.000 kg 



4. 24.000 kg 



7-44. Newton's second law of motion, a = £., 



m 



which can be converted to the form F = ma, 

 indicates that 



1. force is inversely proportional to the 

 product of the mass of a body and its 

 acceleration 



2. acceleration is inversely proportional 

 to the force acting on a body and 

 directly proportional to its mass 



3. acceleration is directly proportional 

 to the force acting on a body and 

 inversely proportional to its mass 



4. the mass of a body is determined by 

 the sum of its acceleration and the 

 external force acting on it 



7-45. One atmosphere of pressure can be 

 expressed as 



1. 1,013.25 mb, 760 mm, or 29.92 in. 

 mercury 



2. 1,013.3 mb, 29.92 mm, or 7.35 psi 



3. 1,033 mm, 760 in. mercury, or 29.9 mb 



4. 1,033 mb, 760 psi, or 29.9 mm 



In items 7-46 through 7-48, select from column I 

 the atmospheric pressure of each altitude in 

 column A under standard conditions. 



A. Altitudes B. Pressure Expressions 



7-46. Sea level 1. 500 mb 



7-47. 18,000 feet 2. 3.68 psi 



7-48. 36,000 feet 3. 760 gm/cm2 



4. 29.92 in. mercury 



Learning Objective: Identify how 

 atmospheric pressure is related 

 to acceleration and mass by 

 Newton's second law, the stand- 

 ards of measurement, and the 

 effect of altitude on pressure. 



7-49. The air pressure upon an aircraft 

 increases as the aircraft 



1 . c 1 imb s 



2. descends 



3. accelerates 



4. turns sharply 



7-50. Which of the following has the greatest 

 effect on atmospheric pressure? 



1. Altitude 



2. Humidity 



3. Density 



4. Temperature 



Learning Objective: Recognize means 

 by which temperature can be measured, 

 scales used to indicate temperature, 

 and the meaning of free air tempera- 

 ture; and solve problems in tempera- 

 ture scale conversions. 



42 



