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Energy Types. Notes part 1. What is Energy?. Energy : the ability to make a physical change or cause a rise in temperature. Energy Units. Joules. calories. 1 chocolate chip has 3000 calories!. Energy in Many Forms. (KE) Kinetic Energy : Energy of mass in
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Energy Types Notes part 1
What is Energy? • Energy: the ability to make a physical change or cause a rise in temperature. Energy Units Joules calories 1 chocolate chip has 3000 calories!
Energy in Many Forms (KE) Kinetic Energy: Energy of mass in motion (runner, car) KE = ½ mass times velocity squared
Energy in Many Forms (GPE) Gravitational Potential Energy: Energy stored in the distance between masses (moon & earth, lifted book) GPE = (mass)(9.8)(height above the earth)
(EE) Elastic Potential Energy: Energy stored in the stretch and compression of molecular bonds (springy, stretchy) Energy in Many Forms (CE) Chemical Energy: Energy stored in atomic bonds (chemical reactions, explosions)
Energy in Many Forms (TE) Thermal Energy: Energy of vibrations of atoms and molecules (determines temperature, often mistakenly called heat)
Match: Energy name with marker Energy Type Marker • Kinetic energy 1. Height & mass • Gravitational PE 2. Temperature • Elastic energy 3. Atomic bonds • Chemical energy 4. Stretch • Thermal energy 5. Speed & mass
KEY: Energy name with marker Energy Type Marker • Kinetic energy 1. Height & mass • Gravitational PE 2. Temperature • Elastic energy 3. Atomic bonds • Chemical energy 4. Stretch • Thermal energy 5. Speed & mass
Which form(s) of energy? http://commons.wikimedia.org/wiki/File:Turkish_Stars_2217.JPG
Energy Conversion: Energy transferred (between objects) or transformed(one type to another), often by a force applied across a distance. (GPE gradually changes to KE as diver falls)
System: • All of objects that are of interest. • Example: Your machine is the system and the surroundings are not the system.
Energy “losses”: • Energy is never lost, but it can leave the system or become less useful. • Example: KE becomes thermal energy or sound.
Conservation of Energy: • A scientific law that the total amount of energy in the Universe does not change (except in nuclear processes). • “Energy is never created or destroyed”, it just moves in or out of the system, or transforms into a less useful form. • Differentfrom recycling, etc.
Explain energy conservation in this scene. Sockeye Salmon
Notes 3: Force Causes Energy Change Work:Converts energy (transformations & transfers). Work is done by applying a force across a distance. Work = Force x distance
Notes 3: Force Causes Energy Change Force:A push or a pull. Only 4 forces in nature: gravity electromagnetic – push/pull strong nuclear – bombs weak nuclear – radioactivity (The last 2 hold the atom together)
Notes 3: Force Causes Energy Change Force of gravity (Fg):The force of one mass on anotherdue to a gravitational field Gravitational field:Surrounds all masses and causes the force of gravity (Higgs)
Notes 3: Force Causes Energy Change • Electromagnetic force (EM Force): The electric and magnetic force between particles. Caused by the EM field. • Electromagnetic field:Surrounds charged particles and causes the EM force (photons).
Energy Conservation - Bar Graphs E(J) E(J) 4 3 2 1 0 4 3 2 1 0 KE GPE EPE TE KE GPE EPE KEY: KE = kinetic energy, GPE = gravitational potential energy EPE = elastic potential energy, TE = thermal energy
Complete the Bar Graphs v = 0 Final Initial E(J) E(J) 4 3 2 1 0 4 3 2 1 0 KE GPE EPE TE KE GPE EPE
How much TE is produced? KE = ½ mv2 GPE = mgh Final: speed v = 0 m/s mass m= 1 kg height h = 15 m g = 10 m/s2 E(J) 200 150 100 50 0 GPE = (1)(10)(15) = 150 J KE GPE EPE TE E(J) Initial: speed v = 20 m/s mass m= 1 kg height h = 0 200 150 100 50 0 KE GPE EPE KE = ½ (1)(20)2 = 200 J