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Energy 8 th Grade

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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.

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Energy can change from one type to another Energy cycle

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

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Types of energy & Energy conversions

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Gas to car Sun to gas Coal to steam Wind to toaster

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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

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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)

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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

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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)

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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.

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Wind Turbines and generators

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Parts of a windmill

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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

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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 3 rd grader?

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

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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

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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?

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Pg 133-134 Blade investigation

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Energy Use (Kill-A-Watt lab)

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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

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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

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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

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Kill-A-Watt lab Pg 136 1. Device/ap pliance 2. Measured Power use (Watts) 3. Measured Power use in kW (W/1000) 4. Time on in 1 day (in use and not in use) 5. Energy used in 1 day (kWh) kW x hours) 6. Energy used in 1 year (x 365) 7. Yearly cost ($0.10 per kWh) example: 20 LCD tv use:120 W Phantom: 4 W.12 kW.004 kW 3 hours 21 hrs.36 kWh.0084 kWh.3684 kWh 134.5 kWh $13.45 Incandesc ent bulb CF bulb VCR (power off and on) Your choice

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

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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?

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Ohms Law Current, Voltage, Resistance

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Ohms Law pg 137 What is Ohms 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)

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Ohms Law Resistance The opposition to the flow of electricity Caused by friction Measured in ohms ( ) Ohms Law Voltage = (current) (resistance) V= I x R V = A x

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A circuit Pg 138

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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)

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Nuclear Fission

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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

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Fission notes pg 139 How is energy produced through nuclear fission? Splitting of an atoms 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

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Fission Reaction

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Nuclear Fission To Energy

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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?

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Solar Energy

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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

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

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Daytime Winter Passive Solar Power Passive Solar Power can also heat homes

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Nighttime Winter Passive Solar Power

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

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

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

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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: 1. Why did you choose that sight for your home and which direction does it face? 2. What type of Solar Power you are using? 3. What more information would be useful?

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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?

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Homework Due Friday Everyone: Read pages 370- 374 Questions 1c, 2c, 3b, 3c Spicy for extra credit: What lead to the nuclear emergencies at Chernobyl, 3 Mile Island, and in Japan? (points depends on quality of answer)

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Fossil Fuels

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Coal Coal is formed from plant remains Coal has potential, chemical energy

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Coal Power plants burn coal turning the chemical energy into thermal energy

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Coal Burning coal heats water Thermal energy turns into kinetic energy of moving water molecules (steam)

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Steam turns the turbine The turbine turns the generator and makes electricity

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Natural gas Natural gas and oil are formed from remains of algae and small animals

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Natural gas Natural gas or oil burns and heats water Water creates steam

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Steam turns turbine Turbine turns generator Generator makes electricity

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Hydropower

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Hydropower uses flowing water to produce electricity Ford dam on the Mississippi River in St. Paul Provided electricity to Ford plant

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Water flows through dam Water turns a turbine Turbine turns a generator Generator makes electricity

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Biofuels

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Biofuels are fuels made from living things Burned to produce energy

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Biofuels Biofuels burn, heat water, make steam Steam turns turbine, turbine turns generator, generator makes electricity

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Geothermal

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Geothermal energy uses Earths heat Hot springs

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Geothermal Pipes are drilled into the crust Liquid is pumped down

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Geothermal Hot liquid/ steam comes up Steam turns turbine, generator Electricity is produced

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Pulling it all together

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Pros and Cons Wind Coal Natural Gas Nuclear Solar Hydro power Biofuel Geothermal What are the pros and cons of generating electricity through different methods?

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JIGSAW Read the articles and use your notes to compile a list of positives and a list of challenges based on the fuel source that you are given We will report out on Tuesday so that all students can gain the knowledge.

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Requirements for Pros and Cons Total of 9 positives or challenges based on current research and data 2 quotes from a primary source. One concerning a positive and one covering a challenge 3 ideas that you may test to make your energy source more efficient, run cleaner, or lower the cost of transferring the raw material into a more useful energy source.

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Product You will create a poster to present the information on your energy source. You have the next two class periods. It is due by the end of class on Tuesday.

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Pg 143-144 CoalOil Natural gasSolar WindBiofuels HydropowerGeothermal

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Carbon cycle game Background: You are a carbon atom. You will track your movement through the carbon cycle as you move between the lithosphere, atmosphere, biosphere, and hydrosphere. Start at your station Write the name and how you exists in that form. Roll the dice and move to the next station. Example:

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Carbon Cycle Atmosphere Hydrosphere Biosphere Lithosphere Carbon sources - release carbon Carbon sinks absorb carbon What is the carbon cycle?

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Greenhouse effect How is the greenhouse effect related to energy? Greenhouse effect Our atmosphere acts like a blanket that insulates Earth and keeps it warm Without any greenhouse effect, Earths average temp would be O o F instead of 57 o F

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Greenhouse effect Greenhouse gases CO2 carbon dioxide CH4 methane N2O nitrous oxide CFCs chlorofluorocarbo ns

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Answers to yellow packet 1. Sun 2. Earths temp changes 3. It would be very cold zero degrees 4. -9. CH4 methane staying the same N2O nitrous oxide - increasing CFC 12 chlorofluorocarbons - decreasing CFC 11 chlorofluorocarbons - decreasing CO2 carbon dioxide increasing Halocarbons CClFI staying the same 10. CO2, N2O 11. CH4, halocarbons, CFCs

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