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Energy

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  1. Energy

  2. Energy • Is the ability to do work • Units = joules (J) What is work?

  3. Chemical Energy • is found in the chemical bonds in • food • fuel and • batteries

  4. Kinetic Energy • Moving energy

  5. Potential Energy • Energy due to position or condition • Water behind a dam or at top of waterfall • Wound up spring e.g. wind up clock

  6. Electrical Energy • Energy in moving charges

  7. Sound • Is a form of energy caused by vibrations • Measured in decibels • Needs a medium to travel through • Echo is reflected sound

  8. Electrical Energy • Energy in moving charges

  9. Heat • Is a form of energy • Joules (J) • Not the same as temperature

  10. Insulator • Does not allow heat or electricity through • (opposite to conductor) • E.g Air trapped in double glazed windows (heat) • E.g. water under wet suit (heat)

  11. Nuclear Energy • Energy found in the nucleus of an atom • (released in atomic bomb or nuclear power station) • Cheap • Dangerous wastes – • radioactive- causes cancer or cures it (in right dose)

  12. Energy Conversions • Convert means • To change • For each energy conversion • Write down • The energy that goes in ( or is in it) • And • The energy that “comes out”

  13. Energy Conversions • Toaster • IN = • Electrical energy • OUT = • Heat energy (and a little light) • BATTERY • IN = • CHEMICAL energy • OUT = • ELECTRICAL energy

  14. Energy Conversions • Hair Dryer • IN = • Electrical energy • OUT = • Heat energy (and sound and kinetic) • Leaf • IN = • solar energy • OUT = • Chemical energy in food

  15. Renewable energy • will never run out • solar, wind, hydroelectric, wave, biomass, geothermal • do not add to greenhouse effect

  16. Hydro-electricity • Electric current generated by the potential and kinetic energy of water • (Dams are wider at bottom due to more pressure deeper down) • Energy change = potential (behind dam)  kinetic (flowing water)  electrical ( in turbine)

  17. Tidal Energy • Renewable energy from the movement of the tides.

  18. Others • Geothermal • Heat energy from under the surface of the Earth • Solar energy • solar panels - expensive & clean • WIND energy • expensive & clean / danger to birds • BIOMASS • Grow trees that re-grow quickly • Use timber to burn for heat

  19. Non renewable energy • Will run out sooner or later • Coal oil turf gas petrol

  20. Fossil Fuel • Coal oil gas turf • Made from dead plants and animal remains • Make CO2 and H2O when burned • Non - renewable Cobalt chloride – bluepink Limewater - milky

  21. Joule • Unit of energy (J) • Unit of work (J) • In food kilojoules are used (kJ)

  22. All in one • Energy is the ability to do work • Kinetic moving energy • Potential energy due to position (high) or condition (stretched or wound up) • Chemical (food fuel and batteries) energy stored in the bonds of chemicals • Solar energy from the sun (light) • Sound energy due to vibrations • Magnetic energy from magnets attracting and repelling • Convert means to change • Conserve means to keep • Law of Conservation of energy • energy cannot be created or destroyed only changed from one form to another • Battery changes chemical energy to electrical energy • Bulb changes electrical energy to light energy • Electrical energy from moving charges (electrons) • Nuclear energy stored in the nucleus (centre) of an atom • Joule (J) the unit of energy

  23. The End

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