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Energy

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Energy

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  1. Energy 8th Grade

  2. Energy REVIEW • What is energy? • Energy – the ability to do work • Potential – stored energy • Kinetic – energy of motion • Energy can change from one form to another.

  3. Energy can change from one type to another – Energy cycle

  4. Conversions of Energy p.130 • How can energy change? • Energy can change (convert) from one form to another • Sun to humans

  5. Types of energy &Energy conversions

  6. Gas to car • Sun to gas • Coal to steam • Wind to toaster

  7. Types of energy • ______________ • Energy that has the ability to do work • Example: Driveshaft on a car, Draw Bow String • ______________ • Energy stored in the bonds between atoms and molecules • Examples: Food, Gasoline • _______________ • Energy carried by moving electrons in an electrical conductor • Example: Electricity

  8. Types of energy • _____________ • Energy from Electromagnetic Waves • Example: the Sun • ________________ • Energy related to temperature (due to moving atoms and molecules) • Example: Creation of Steam from water • _________________ • Energy released when atoms are split (fission) or added (fusion) • Example: Nuclear reactor (fission) Stars (fusion)

  9. Types of energy • Mechanical • Energy that has the ability to do work • Example: Driveshaft on a car, Draw Bow String • Chemical • Energy stored in the bonds between atoms and molecules • Examples: Food, Gasoline • Electrical • Energy carried by moving electrons in an electrical conductor • Example: Electricity

  10. Types of energy • Radiant Energy • Energy from Electromagnetic Waves • Example: the Sun • Thermal Energy • Energy related to temperature (due to moving atoms and molecules) • Example: Creation of Steam from water • Nuclear Energy • Energy released when atoms are split (fission) or added (fusion) • Example: Nuclear reactor (fission) Stars (fusion)

  11. Discussions: • Describe one of your energy uses to a table partner. • Where does that energy start in the energy cycle • What might be the pathway for that energy to get to you.

  12. Wind Turbines and generators

  13. Parts of a windmill

  14. Design a wind turbine • Criteria: • Work with your table • Use materials available • Make it spin • All parts must be taken apart before the end of class • Please do not break or damage the materials • Complete reflection

  15. Reflection – pg 131 (below notes) • Write down what DID and DID NOT work when building your windmill. (we will reference this later) • How would you explain this to a 3rd grader?

  16. Quick review: work and power • Force = mass x gravity • Work = Force x Distance • Power = Work time

  17. Goal for today • Rebuild your windmill and lift as many washers as you can 0.5m • Calculate the Work and Power required to lift your maximum amount of washers

  18. Page 131: Day 2 reflection • Work and power calculations. • What part of Design was the most difficult? • How might you go about your design differently the next time?

  19. Pg 133-134 • Blade investigation

  20. Energy Use (Kill-A-Watt lab)

  21. Energy Use Notes: Pg 135 • How much energy do you use? • Energy – the amount of work done by an appliance • Power – the RATE at which energy is used • Electrical power is measured in Watts

  22. Energy use notes continues • 1 Watt = the power needed to raise 100g, 1meter in 1 second • 1 kilowatt (kW) = 1,000 watts • Phantom/ vampire load – energy that appliances use even when they are turned off

  23. pg 135 (below notes) • Write 3 things you genuinely learned from the reading • When done, start to copy down the data table on page 136

  24. Kill-A-Watt lab Pg 136

  25. Below data table • Answer questions 1-7 from the Kill-A-Watt lab sheet.

  26. Conclusion questions - • What was the largest power user? • Were you surprised by any of the appliances? • Will this change at all how you might use electricity?

  27. Ohm’s Law Current, Voltage, Resistance

  28. Ohm’s Law pg 137 • What is Ohm’s law and how do you use it? • Current • The FLOW of electrons in a wire • Measured in amperes (A) • Voltage • The PRESSURE available to move electrons • Measured in volts (V)

  29. Ohm’s Law • Resistance • The opposition to the flow of electricity • Caused by friction • Measured in ohms ( Ω ) • Ohm’s Law • Voltage = (current) (resistance) • V= I x R • V = A xΩ

  30. A circuit Pg 138

  31. Ohms law practice • Complete the practice questions below the circuit picture on page 138. PLEASE do all questions. Thank you! • When done, explain the relationship between I, V, and R in this picture. (below your practice questions)

  32. Nuclear Fission

  33. Fusion vs. Fission Fusion • Combining of smaller elements • Occurs in Nature • Produces many radioactive waves • Fuel is Hydrogen Fission • Breaking of larger elements • Does not occur naturally • Little radioactive waves produced • Fuel is Uranium

  34. Fission notes pg 139 • How is energy produced through nuclear fission? • Splitting of an atom’s nucleus into two smaller nuclei • Uranium-235 hit with a neutron • U-235 splits into two smaller nuclei and two neutrons • Those neutrons hit more U-235 setting off a chain reaction • As nuclei split, energy is released as heat

  35. Fission Reaction

  36. Nuclear Fission To Energy

  37. Wrap-up: • Discuss with a partner then write in your notes: • What are two differences between fission and fusion? • Do the benefits of energy generation from nuclear fission outweigh the risks? Why or Why not? • If you were the POTUS what would your energy plan be concerning nuclear energy?

  38. Solar Energy

  39. Solar Energy Notes pg. How does passive solar energy work? • The sun radiates infrared waves or thermal energy to Earth • This thermal energy heats Earth

  40. Passive Solar Example Notes • When we use the sun to heat things directly, we are using passive solar power • This is a solar oven

  41. Daytime Winter Passive Solar Power • Passive Solar Power can also heat homes

  42. Nighttime Winter Passive Solar Power

  43. Active Solar Energy How does solar energy create electricity? • The sun also provides light energy in the form of visible light waves

  44. Active solar energy • Solar cells on solar panels convert this light energy into electricity

  45. Active solar energy • Sunlight hits silicon on the solar panels and makes electrons move • The moving electrons create electricity

  46. Sight Selection • You have been commissioned to build a Solar Powered House in a specific area about 3 kilometers in square area • You can use either Active or Passive Solar Power or both • You must answer the following 3 questions about your placement: • Why did you choose that sight for your home and which direction does it face? • What type of Solar Power you are using? • What more information would be useful?

  47. Wrap-up • Share your design with a person who is at a different table: • Answer the following: • Why did you pick your sight selection? • Did your partner convince you that there is a better sight?