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WorksheetBeinf orcement

LESSON 18.)erne xit I• LEVEL 2J

Saturation and HumidifyVerncna, a middle school student, began studying about evaporation and conden-sation in science class on Monday,

1. How cculdVernon explain the difference between evaporation and condensa-tion to his friend Chris, who missed school on Monday?

Refer to the table to answer questions 2 and 3.

2!. On Monday the temperature was30°C, On Tuesday, the temperaturedropped 10 degrees. The amount ofwater vapor in a cubic meter of airwas 15 g on both days.

a, On which day was the air nearlysaturated with water vapor?

b, Is more water vapor po&ible inwarmer or colder air?

Temperature

10°G

20°C

30°C

40°C

Amount of WaterVapor Needed toSaturate a CubicMeter of Air

17g

30 g

51 g

c. On which day did Vernon stay drier while running track?

d. On which day was the relative humidity higher?

3, Vernon and his classmates calculated Monday's and Tuesday's relative humidity. The formula is as follows.

Relative Humidity = _. ..... ________ x 1QOAmount of Water Needed to Saturate Air

a. What was the relative) humidity on Monday?

b. Different members of the ciass obtained different figures for the relativehumidity on Tuesday. Circle the correct figure

88% 30%

16

Name Class —. Date

t.

-

-

-• . -:

"I

i

r-100

I

-90

-80

-70

-60

^50

-40

r30

-20

-10t r\Jirllf "10

llr -20

1Thermometer

(dry)

*i

1—i

1

r 100

i-90

-80

-70

-60

rso

-40

-30

h20

MO

-0

h-10

-•20

i.'O:Thermometer

(wet)

RELATIVE HUMIDITY

Dry-BulbThermometerReadings (°C)

1011121314

15161718192021222324

252627282930

Difference Between Wet-and Dry-Bulb ThermometerReadings (°C)

7 2 3 4 5

88 77 66 55 4489 78 67 56 4689 78 68 58 • 4889 79 69 59 50gij 79 70 60 51

90 80 71 61 5390 81 71 63 5490 81 72 64 5591 82 73 65 5791 82 74 65 58

91 83 74 66 5991 83 75 67 6092 83 76 68 6192 84 76 69 6292 84 77 69 62

92 84 77 70 6392 85 78 71 6492 85 78 71 6593 85 78 72 6593 86 79 72 6693 86 79 73 67

Figure 2

67. In Figure 2, what is the temperature of the dry bulb? The wet bulb?

68. Why is the temperature of the wet-bulb thermometer in Figure 2 lower than the drybulb thermometer?

69. How many degrees apari are (he readings on the rwo thermometers in Figure 2?

70. Using (he table in Figure 2, what ts the humid.it)' of the air based on vhe data recordby the rwo thermometers shown;'

71. Using the table in Figure 2, if the humidity of the air at the present lirne is 54 percefand a dry bulb thermometer shows 16°C, what should be the temperature of the wetbulb thermometer?