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Good Morning!

Good Morning!. Take out your homework packet Turn to 17.4 practice (P = I x V) We will go over answers as a class. Wednesday, May 13, 2015. Learning Target: I can assess what I need to study before my test on Friday. Today: Go over answers to homework packet Turn in!

MikeCarlo
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Good Morning!

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  1. Good Morning! • Take out your homework packet • Turn to 17.4 practice (P = I x V) • We will go over answers as a class

  2. Wednesday, May 13, 2015 • Learning Target: I can assess what I need to study before my test on Friday. • Today: • Go over answers to homework packet • Turn in! • Work time on Review Packet • *Practice Test/Review tomorrow!!

  3. Warm Up • What is magnetic declination? • Draw a sketch of the Earth: • Where is the geographic south pole? • Where is the magnetic south pole?

  4. Work Time • Goals: • Turn in Homework Packet • Get majority of Review Packet finished • Improve class test average! –we’re a team!  • Tomorrow: • Review packet should be done • Practice test/assess where we are at!

  5. Exit Question a. Your cell phone charger uses 8 amps of current when plugged into a 120 volt outlet. What is the power rating of the toaster in watts? b. What is the power rating in kilowatts? c. How many kilowatt-hours does your charger use if you use it for 14 hours a month? d. The utility company charges $0.12 per kilowatt-hour. What does it cost you to use the charger for that month?

  6. Warm Up • At which point(s) (A, B, C, or D) could the SOUTH pole of a magnet be placed in order to make the rotor spin counter clockwise?

  7. Warm Up • Which way is the north pole in the electromagnet below? • Which way will the north end of a needle on your compass point?

  8. Chapter 17 17.4 Generating Electricity

  9. Generating Electricity • Lots of heat energy is generated from coal, gas, and oil • Most of the heat energy is “lost” as unusable energy

  10. Generating Electricity • Nonrenewable resources: not replaced as it is used (ex: coal, oil, natural gas) • Renewable resources: a natural resource that can be replaced (ex: falling water, Sun, wind)

  11. Electricity from Fossil Fuels • Three major fossil fuels: coal, oil, natural gas • Take a long time to form!

  12. Better(?) Forms of Energy • Nuclear Energy • Wind Energy (renewable) • Solar Energy (renewable) • Hydroelectric [water] Energy (renewable) • Geothermal Energy (renewable) • Biomass Energy (renewable)

  13. Electricity from Nuclear Energy • Nuclear energy does not pollute the air like fossil fuel power plants do.

  14. Electricity from Nuclear Energy • Disadvantage = storage of nuclear waste • Uranium fuel from the reactor stays dangerously radioactive for a long time.

  15. Renewable: Wind Energy California was the first U.S. state to build large wind farms. Wind farms can disturb natural habitats, and can perhaps scar a large area of scenery.

  16. Renewable: Solar Energy A solar cell (also known as a photovoltaic cell) can convert solar energy to electricity. • The Sun’s energy is often called solar energy.

  17. Renewable: Hydroelectric Power Hoover Dam • A hydroelectric (or hydropower) plant uses energy from falling water to generate electricity.

  18. Renewable: Geothermal Energy Geothermal power plants use Earth’s internal heat energy, in the form of water or steam, to produce electricity. A geothermal heat pump system takes advantage of the relatively constant temperature of Earth’s shallow ground.

  19. Renewable: Biomass Energy Biomass is organic material from plants or animals. In waste-to-energy plants, renewable solid waste is burned to produce electricity, which also creates some air pollution.

  20. Quick Check! List 3 fossil fuels. Are fossil fuels nonrenewable or renewable? EXPLAIN. List 3 renewable resources.

  21. Electrical Power Electrical power is measured in watts, just like mechanical power. • Electrical power: the rate at which electrical energy is changed into other forms of energy such as heat, sound, or light. Power = current x voltage P = IV

  22. Electrical Power • Utility companies charge customers for the number of kilowatt-hours (kWh) used each month. • A kilowatt-hour is a unit of energy, not power # of kilowatt-hours = # of kilowatts x hours

  23. Electrical Power Example a. A toaster uses 12 amps of current when plugged into a 120 volt outlet. What is the power rating of the toaster in watts? b. What is the power rating in kilowatts? c. How many kilowatt-hours does the toaster use if you use it for 2.5 hours a month? d. The utility company charges $0.15 per kilowatt-hour. What does it cost you to use the toaster for that month?

  24. Electrical Power Example a. A microwave uses 2 amps of current when plugged into a 80 volt outlet. What is the power rating of the microwave in watts? b. What is the power rating in kilowatts? c. How many kilowatt-hours does the microwave use if you use it for 8.2 hours a month? d. The utility company charges $0.25 per kilowatt-hour. What does it cost you to use the microwave for that month?

  25. Electrical Power Example a. A computer uses 5 amps of current when plugged into a 120 volt outlet. What is the power rating of the computer in watts? b. What is the power rating in kilowatts? c. How many kilowatt-hours does the computer use if you use it for 28 hours a month? d. The utility company charges $0.12 per kilowatt-hour. What does it cost you to use the computer for that month?

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