Earth Systems & Resources unit test
A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.
Recharge zone
Soil texture triangle
Monsoon
Thermohaline circulation
Albedo
Aquifer and water table
Saltwater intrusion
Insolation and the seasons
Soil pH and nutrient availability
Soil formation factors
La Niña conditions
Confined vs unconfined aquifer
Short answer 1. Define or explain: Upwelling
3 ptsShort answer 2. Define or explain: El Niño and La Niña
3 ptsShort answer 3. Define or explain: Why the troposphere cools with height and the stratosphere warms
3 ptsShort answer 4. Define or explain: Soil erosion causes
3 ptsFree response
10 ptsThis course has no free-response prompt tagged to this unit, so one from elsewhere in the course is used. It is still worth writing — the skill transfers.
ANALYZE AN ENVIRONMENTAL PROBLEM USING CALCULATIONS. A coal-fired power plant generates 500 megawatts of electricity and operates continuously. The plant burns coal with an energy content of 25,000 kilojoules per kilogram, and the overall efficiency of converting the chemical energy in the coal to electricity is 40 percent. The coal contains 2.0 percent sulfur by mass. Assume the plant operates 8,000 hours per year. Show all work and include units in your answers.
A. Calculate the rate, in kilojoules per second, at which the plant must consume energy from coal to produce 500 megawatts of electricity.
B. Calculate the mass of coal, in kilograms, that the plant burns per second.
C. Calculate the mass of coal, in kilograms, that the plant burns per year.
D. Calculate the mass of sulfur, in kilograms, released per year if no pollution controls are used.
E. Describe one air pollution control technology that would reduce sulfur emissions from this plant, and explain how it works.
F. Describe one environmental consequence of sulfur emissions from coal combustion, and explain the mechanism.