Forms of Energy:
Facts: |
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Energy Definition |
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•Energy is defined as the ability to cause change. |
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Law of Conservation (The Cannot-Cannot-Can) |
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•Energy cannot be Created |
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•Energy cannot be Destroyed |
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•Energy can change Forms |
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Forms of Energy |
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•Chemical Energy (Energy stored in the bond energy between atoms in a molecule or released/absorbed in a chemical reaction.) |
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•Heat Energy (Associated with the movement of atoms or molecules and by the friction between materials.) |
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•Electromagnetic Energy (Associated with the Electromagnetic Spectrum and the transfer of energy by radiant energy.) |
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•Mechanical Energy (Associated with the movement of large objects or gravitational position of objects, it will also include sound.) |
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•Nuclear Energy (Associated with fission and fusion the breaking and making of atoms. Violates the conservation of matter.) |
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•C.H.E.M.N. An imaginary word used to remember the five forms of energy. Note, the first four letters match up to chemical energy. |
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Units of Energy |
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•The Joule (J) or Newton meter (N•m) is defined as a force applied through a distance. |
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•The calorie (cal) a unit of heat energy. 1 cal = 4.184 J |
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•One calorie is the amount of energy needed to raise the temperature of water 1oCelsius. |
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•The kilocalorie (kcal) is one food Calorie that you see in a nutrition information box. |
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| States of Energy
Facts: |
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Energy can be in one of Five Forms |
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For each form Energy can be in one of Two States. |
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Law of Conservation of Energy Applies |
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•Energy can change states from KE to PE and back to KE |
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-skaters use PE to KE back to KE |
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-rollercoasters use PE to KE back to KE |
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-pendulums use PE to KE back to KE |
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Kinetic Energy |
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•The Energy of Motion |
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•For Mechanical Energy KE=1/2(mv2) |
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-KE (kinetic energy) J or N•m |
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-m (mass) kg |
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-v (velocity) m/s |
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Potential Energy |
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•The Energy of Position or Stored Energy |
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•For Gravitational Energy PE=mgh |
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-PE (potential energy) J or N•m |
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-m (mass) kg |
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-g (gravity or acceleration) m/s/s or m/s2 9.8m/s/s on Earth |
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-h (height) m |
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•Other Forms of Potential Energy (Mechanical) |
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-springs |
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-rubber bands |
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| Methods of Energy Transfer: |
Transfer of Heat Energy |
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Using a Medium |
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•By Conduction (by touch) |
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•By Convection (by the circulation of a fluid) |
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Does Not Need a Medium |
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•By Radiation (by an electromagnetic wave) |
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Heat Equation |
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•Q = m c (Δ T) |
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•Q = heat energy (calories) |
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•m = mass (grams or kilograms depends on c |
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•c = specific heat (cal/(gram oC)) |
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•Δ = delta a Greek letter meaning the change used as a subtraction between two temperatures. |
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•T = temperature (oC) |
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Vocabulary |
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•Conductor |
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•Insulator/Insulation |
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•Vacuum |
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•Reflective |
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Transfer of Mechanical Energy |
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Always Requires a Medium |
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•Compressional Waves |
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•Transverse Waves |
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•Water Waves |
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Wave Equation |
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•Wave Speed = ws (meter/second, m/s) |
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•Wavelength = λ (meter, m) |
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•Frequency = f (Hertz, Hz) |
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•Equation is ws = λ ( f ) |
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Vocabulary |
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•Amplitude (energy of a wave) |
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•Crest (top of a wave) |
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•Trough (bottom of a wave) |
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•Hertz is defined as 1/time (1/second, 1/s, s-1) |
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Transfer of Radiant Energy |
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Does Not Require a Medium |
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•Always a Transverse Waves |
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•Always an Electromagnetic Wave |
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-an electric field traveling as a transverse wave |
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-a magnetic field traveling as a transverse wave but at a 90o angle to the electric field |
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•Travels at the speed of light |
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-c = speed of light = 3x108m/s |
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•Wave Equation |
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-c = λ ( f ) |
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Organized into the Electromagnetic Spectrum |
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•Radio Waves |
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-associated with long wavelengths |
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-associated with low frequencies |
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•Microwaves |
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•Visible Light (separates into the colors of the rainbow from lowest frequency red to highest frequency violet) |
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-red |
-green |
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-orange |
-blue |
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-yellow |
-violet |
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•Ultraviolet Rays (UV Rays) |
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•X-Rays |
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•Gamma Rays |
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-associated with short wavelengths |
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-associated with high frequencies |
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Applets:
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Heat Energy
In this applet you will be able to manipulate the temperature and see how matter behaves. This example applies to the matter in the gas state. Using your imagination you could see how it applies to all states. |
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Kinetic Energy Potential Energy Skate Park
In this applet you will be able to manipulate the design of the shape, the mass of the skater, the location (Earth, space, Jupiter) and map out how values are changing graphically. |
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Back to Top Forms and States of Energy
Back to Methods of Energy Transfer |
Property of SOESD |
November 30, 2008 |
