Climate & Calculating BTU’s in Environmental Science

1. Climate & Calculating BTU’s in Environmental Science By Dr. Rick Woodward

2. Saving Math to the Last 1. There are four free response questions. 2. All four questions are weighted equally. 3. The suggested time is about 22 minutes for answering each question. 4. There will only be one out of the four questions that focuses specifically to math calculations involving conversions.

3. Saving Math to the Last 5. Calculators are not allowed and you must show all of your work in order to receive credit. 6. Math is only a small percentage of the AP Environmental Exam. I have been focusing on conceptual knowledge of the environment and intuitive test taking skills.

4. This Thursday’s Examwill have 50 multiple Choice Questions & 1 Math Free Response It Will cover: 1. The parts of a nuclear reactor and their specific functions. 2. How energy is converted into electricity. 3. Global Warming Gases. 4. Heavy Metals 5. Thirty questions pulled from Barron’s prep questions.

5. Reviewing Climate Change

6. What are the Greenhouse Gases?

9. Atmosphere 1. The gas that is responsible for trapping most of the heat in the lower atmosphere is a. Water vapor b. ozone c. carbon dioxide d. oxygen e. nitrogen

10. Correct Answer a. Water Vapor

12. Cloud Formation Review

13. Monsoons 2. Characteristics or requirements of a monsoon include all of the following EXCEPT a. A seasonal reversal of wind patterns. b. Large land areas cut off from continental air masses by mountain ranges and surrounded by large bodies of water. c. Different heating and cooling rates between the ocean and the continent. d. Extremely heavy rainfall. e. Heating and cooling rates between the oceans and the continents are equivalent.

14. Correct Answer e. Monsoons are caused by winds from the southwest or south that bring heavy rainfall to southern Asia in the summer. -They are created by temperature gradients that exist between ocean and land surfaces.

16. Albedo 3. The surface with the lowest albedo would be a. Snow b. Ocean c. Forest d. Desert e. Black topsoil

17. Correct Answer e. Albedo is a measure of reflection of sunlight from a surface. Dark objects absorb energy, light surfaces reflect sunlight. -Dark topsoil would absorb the most energy and, therefore, would reflect the least resulting in the lowest albedo.

19. Jet Streams 4. Jet streams travel primarily a. North to South b. South to North c. East to West d. West to East e. In many directions depending on a multitude of factors

20. Correct Answer d. Jet streams are large-scale upper air flows that travel from west to east. -They are located between 3 ½ an 7 ½ miles above the Earth’s surface.

21. Jet Stream A. The jet stream is a current of fast moving air found in the upper levels of the atmosphere.

22. Low Pressure vs. High Pressure Air Masses 5. A low-pressure air mass is generally associated with a. Hot, humid weather b. Fair weather c. Tornadoes d. Cloudy or stormy weather e. Hurricanes

23. Correct Answer d. Cloudy or stormy weather

24. What’s a Watt? A. The basic unit of energy is the watt (named after Scottish engineer James Watt). B. An incandescent light bulb uses 25-100 watts.

25. What’s a Kilowatt? C. One kilowatt (kW) is equal to a thousand watts.

26. What is a Kilowatt Hour (KWh)? D. When electricity use is measured over time, it is measured in kilowatt hours (kWh) .

28. What is a kilowatt hour? E. How many kilowatts (kW) of electricity are used (or produced) over how many hours? F. Leaving a 100 watt light bulb on for 10 hours will use 1,000 watt hours – or one kilowatt hour. G. Your electricity bill probably measures your electricity consumption in kilowatt hours.

29. What is a Megawatt? H. The capacity of large-scale power plants is usually on the scale of megawatts (MW). I. One MW is equal to one million watts, so we’re talking about a very large amount of energy

30. What is a megawatt? J. As a general rule of thumb, each MW of a coal plant’s power plant capacity can supply around 650 average American homes (Assuming 10,000kWh/year demand of average US home and 75% capacity for a coal plant).

31. What’s a gigawatt? K. For very large-scale power plants, capacity is often discussed in gigawatts (GW). L. A GW is one billion watts, or one thousand MW.

32. What’s a gigawatt? M. The ill-fated Chernobyl nuclear power plant, for example, had a capacity of 4,000 MW – that’s 4 GW - which accounted for about 10% of Ukraine’s electricity production at the time.

33. Nuclear Reactor Diagram

34. Nuclear Reactor

35. What’s a gigawatt? N. China’s Three Gorges Dam, the world’s largest power plant of any kind, which will eventually be 22.5 GW.

36. Wednesday (January 25, 2012) Today’s agenda: 1. Brief review of BTU’s 2. Free Response Question 3. Test tomorrow with one redemption assignment worth 10.5 pts. (30 Questions come from Barron’s multiple choice question and twenty come from me (global warming and nuclear power)) 4. Collecting your extra credit Ms. Benki signature from Saturday and show me your paper work

37. General Information on Energy Units 1 Gallon of water = 8 pounds 1 BTU = The amount of energy required to raise the temperature of 1 pound of water by degree F. 1 Kilowatt-hour – 3,400 BTU’s Energy questions are all about conversions and simple math.

38. **Distinguishing Between Power & Energy A. Power has a unit of Watts (W). Energy has the unit Joule (J) and is equal to power over the time dimension. 1J = 1Ws. B. When converted into Watt hours, it is simply done by multiplying by 3600.Hence, 1Wh = 3600 Joule.

39. BTU’s = British Thermal Units A fundamental unit of energy in the English system. B. The amount of heat required to raise the temperature of 1 pound of water 1 degree Fahrenheit. 1 gallon of water = 8 pounds -Problems involving calculations: 1. They give you assumptions 2. They give you extra information that may not be used. 3. Always show your work 4. No Calculators

40. BTU Some Fun BTU Facts: 1. Gas-fired electrical power plant. 2. 15,000,000 kW-h of electricity every 24 hours (1 day) 3. Plant requires 13,000 BTUs of heat to produce 1 kW-h of electricity 4. 1 ft3 of natural gas supplies 1000 BTUs of heat energy

43. Go to Water Heater Question • Then pass out sample BTU Question.

44. Calculation of BTUs 1. Calculate BTUs of heat needed to generate electricity produced in 24 hours. (1) Start with an equal sign = (2) Next write down the units you want to be in = BTUs (3) Next, what did you have to start with? The answer to this question is 24 hours 24 hours = BTUs 1

45. Calculation of BTUs (4) Next, what do you know about hours so that you can cancel the term? The answer is that 15,000,000 kW-h are produced every 24 hours. 24 hours x 1.5 X 107 kW-h = BTUs 1 24 hours

46. Calculation of BTUs Note: We are now in kW-h and we have to end up in BTUs. Was there any information regarding kW-h and BTUs? The answer is yes. 13,000 BTUs are required for every 1 kW-h. 24 hours x 1.5 x 107 kW-h x 13,000 BTUs = 1 24 hours 1 kW-h

47. Calculation of BTUs Correct Answer = 2.0 x 1011 BTUs per day

48. Next Question Calculate the number of cubic feet of natural gas consumed by the power plant each hour. Calculation Set Up 2.0 x 1011 BTUs x 1 ft3 x 1 day = 1 day 1,000 BTUs 24 hours

49. Correct Answer = 8.3 x 106ft3 natural gas per hour

50. Water Heater Question worth 6 points 1. They give you assumptions 2. Other information. 3. There may be information that you do not need to use. 4. Always label your parts/components of question in essay. 5. You don’t have to answer the questions in order. Water heater 50 degrees Fahrenheit. Assume water heater is 100% efficient. Use 40 gallons of water per day. Heat water up to 140 degree One gallon of water = 8 pounds No calculators can be used on test. What is a BTU: British Thermal Unit Defined: The energy needed to raise one gallon of water by one degree Fahrenheit. One Kilowatt hour = 3400 BTU