Date Due: Wednesday, 29 September 1999
The total maximum points were 100. Point distribution for each question noted below.
a. Mark and label the North and South Poles.
b. Draw and label the Equator.
c. Draw and label the i.) Tropics of Cancer and Capricorn and ii.) the Arctic and Antarctic Circles.
d. Mark with the letter "V" that latitude where the sun appears to be directly overhead at local solar noon.
e. Mark with the letter "T" that latitude at the edge of the polar night where the sun appears to be just on the local horizon at local solar noon.
(20 pts)
21 MARCH 21 JUNE 23 SEPTEMBER 23 DECEMBERSee also satellite images (courtesy of DataStreme and Project Atmosphere, the education initiative of the American Meteorological Society)
21 MARCH 21 JUNE 23 SEPTEMBER 23 DECEMBER
(2 pts)
| 1.97 cal per sq. cm. per min or 1372 Watts per sq.
meter.
These values were provided and discussed in lecture. |
b. A mythical planet has an orbit with an average planet-sun distance exactly half that of the earth's. What would be the solar constant for this mythical planet? [Hint: make use of your answer from above.]
(4 pts)
| The inverse square law means that the planet at one half the distance
would have 4 times (2 squared) the amount of energy per unit area per unit
time.
7.88 cal per sq. cm. per min or 5488 Watts per sq. meter. |
c. What is the planetary albedo of the planet earth?
(2 pts)
| From lecture:
Planetary albedo = 30 - 31 percent . |
a. Which object would radiate more energy?
b. Which object would radiate more of its energy at a shorter wavelength?
(1 pt. each or 2 pts)
| a. A (A consequence of Stefan-Boltzmann law)
b. A (A consequence of Wien's Displacement law) |
a. What is the wind chill equivalent temperature if the ambient air temperature were 15°F and the wind speed were 10 mph?
b. What is the wind chill equivalent temperature if the ambient air temperature remained at 15°F, but the wind speed increased to 25 mph?
c. What has caused the difference between your answers a and b above? Why?
d. To what temperature does your automobile reach in part a? in part b?
(11 pts)
| Note that Table 3.3B (for English units) should be used:
a. -3° F is the wind chill equivalent temperature b.-22° F is the wind chill equivalent temperature c. The increased wind speed causes the difference in the wind chill equivalent temperatures. The convective heat loss from the human body increases with increased winds. A statement about the air being colder is not correct. d. The temperature of your automobile can only reach the ambient air temperature of 15° F in both cases, and go no lower. The wind-chill equivalent temperature is not relevant here. However, in the second case, the stronger winds would hasten the cooling process. |
a. How much energy is required to entirely melt 1 gram of ice at the ice point?
b. How much energy is required to evaporate 1 gram of liquid water at room temperature?
c. How would the temperature of 1 kilogram of liquid water originally at 20°C change if 5000 calories were used in the heating process (assume no phase transformations)? If a temperature change would take place, indicate the amount of change (and the direction of the temperature change).
[Please show your work and include units!]
(11 pts)
| a. 80 cal (This is the latent heat of melting.)
b. 590 cal (Note: The latent heat of evaporation is a function of temperature, being 590 cal at 20° C and decreasing to 540 cal at 100° C.) c. 5 deg C heating Since 1 calorie is the heat needed to raise 1 gram of water 1 Celsius degree, then 5000 calories would raise 1000 grams by 5 degrees (making the liquid warm from 20° C to 25° C) |
Last revision: 23 September 1999
Produced by Edward J. Hopkins, Ph.D. Department of Atmospheric and Oceanic Sciences University of Wisconsin-Madison, Madison, WI 53706 hopkins@meteor.wisc.eduURL Address: aos100/homework/f9hmk02a.htm
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