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Energy. Energy. Is the ability to do work Units = joules (J). What is work?. Chemical Energy. is found in the chemical bonds in food fuel and batteries. Kinetic Energy. Moving energy. Potential Energy. Energy due to position or condition Water behind a dam or at top of waterfall
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Energy • Is the ability to do work • Units = joules (J) What is work?
Chemical Energy • is found in the chemical bonds in • food • fuel and • batteries
Kinetic Energy • Moving energy
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
Electrical Energy • Energy in moving charges
Sound • Is a form of energy caused by vibrations • Measured in decibels • Needs a medium to travel through • Echo is reflected sound
Electrical Energy • Energy in moving charges
Heat • Is a form of energy • Joules (J) • Not the same as temperature
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)
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)
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”
Energy Conversions • Toaster • IN = • Electrical energy • OUT = • Heat energy (and a little light) • BATTERY • IN = • CHEMICAL energy • OUT = • ELECTRICAL energy
Energy Conversions • Hair Dryer • IN = • Electrical energy • OUT = • Heat energy (and sound and kinetic) • Leaf • IN = • solar energy • OUT = • Chemical energy in food
Renewable energy • will never run out • solar, wind, hydroelectric, wave, biomass, geothermal • do not add to greenhouse effect
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)
Tidal Energy • Renewable energy from the movement of the tides.
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
Non renewable energy • Will run out sooner or later • Coal oil turf gas petrol
Fossil Fuel • Coal oil gas turf • Made from dead plants and animal remains • Make CO2 and H2O when burned • Non - renewable Cobalt chloride – bluepink Limewater - milky
Joule • Unit of energy (J) • Unit of work (J) • In food kilojoules are used (kJ)
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