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Energy. What is Energy ?. The ability to do work or cause a change. When an object or living thing does work on another object , some of its energy has been transferred . Energy is measured in joules, the same units as work .
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WhatisEnergy? • The ability to do work or cause a change. • When an object or living thingdoeswork on anotherobject, some of itsenergy has been transferred. • Energyismeasured in joules, the sameunitsas work. • Power is the rate atwhichenergyistransferred. • Power= energytransferred/time
KineticEnergy • Kineticcomesfrom the greekwordkinetos, whichmeans to move • Kineticenergyis the energy an object has due to its motion. • There are 2 factorsthat affect kineticenergy: • Mass • Velocity • Think about a golf ball and a bowling ball
PotentialEnergy • Is energythat has the potential to do work. • Gravitationalpotentialenergyisrelated to the object’sheight. • The higher the object or the more weight an object has, the greater the gravitationalpotentialenergy • Elasticpotentialenergyisassociatedwithobjectsthatcanbestretched or compressed.
Forms of Energy • Mechanicalenergyisassociatedwith the position and motion of an object. • = potentialenergy + kineticenergy
Thermal Energy • Is the total potential and kineticenergy of the particles in an object. • Ex. icecream, lava
ElectricalEnergy • The energy of electrical charges • Depending on whether the charge ismoving or storeddetermineswhether or not itispotential or kineticenergy.
ChemicalEnergy • Is potentialenergystored in the chemical bonds thatholdchemical compounds together. • Almosteverythingyousee, touch, or taste iscomposed of chemical compounds. • Whenchemical compounds are broken, new compounds mayform, releasing energy.
NuclearEnergy • Is stored in the nucleus of atoms • Is releasedwhenduring a nuclearreaction • Fission-nucleus splits • Fusion-nucleifuse • Continuously happening in the sun, releasing tremedousamounts of energy
ElectromagneticEnergy • Is the energy of light and otherforms of radiation • The sunlight weseeeachdayiselectromagneticenergy • It travels in waves-x rays, uv rays, radio wavesand microwaves
Energy Transformations • Are a change from one form of energy to another • Single tranformation • Toastingbread • Electrical to thermal • Cell phone • Electricalto electromagnetic • Your body • Chemical to mechanical
Energy Transformations • Multiple transformations- often a series of energy transformations isneeded to do work • Ex- lighting a match • Thermal to chemical to thermal to electromagnetic
Energy Transformations • One of the mostcommonforms of energy transformation itbetweenpotential and kinetic • Ex. juggling, pendulum, pole vault
Conservation of Energy • The lawof conservation of energy states thatenergycannotbecreated or destroyed • So whydoes a top stop spining? • Friction= mechanical to thermal
Energy and Fossil Fuels • Plants of ancientforestsprovide the energystored in fossil fuels • Coal, petroleum and naturalgas are fossil fuels • Wheredidfossil fuels gettheirenergy? • The SUN • Fossil fuels canbeburned to release thatenergy, thisisknown as combustion