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Energy. SI units. energy = joule (J) = 1 Nm = 1 kg ·m 2 /s 2. Conservation. Energy can be converted from one form to another, but it cannot be created or destroyed in an ordinary chemical or physical change. Two big classes. Kinetic – energy of motion Potential – stored energy.
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SI units • energy = joule (J) = 1 Nm = 1 kg·m2/s2
Conservation • Energy can be converted from one form to another, but it cannot be created or destroyed in an ordinary chemical or physical change.
Two big classes • Kinetic – energy of motion • Potential – stored energy
Potential Energy • Energy stored due to • position (where it is) • Example: GPE, spring energy • composition (what it is made of) • Example: chemical, nuclear
Energy • thermal/heat (more later) • electromagnetic / radiant / light • Mechanical energy ME = KE + GPE • electrical • sound
Energy equations • KE = mv2/2 • GPE = weight x height = mgh • ME = KE + GPE
Radiation Conduction Matter not required Can occur in space Waves Objects touch each other Collisions of atoms Heat transfer From hot to cold Matter required Currents in a fluid Different densities created Objects touch each other Matter required Matter not required From hot to cold Can occur in space Currents in a fluid Collisions of atoms Different densities created Waves Read pages 280-284. Directions: Put phrases of the other box into the Venn diagram. Zones may have no phrases, one phrase, or more than one phrase. Use all the phrases Convection
heat -v- temperature • Heat = total amount of energy of moving particles • Temperature = average energy of the moving particles.