Ch.9, Sec.2

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Ch.9, Sec.2 Energy Conversions

• energy conversion the change of one form of
  energy to another

• Examples of Kinetic Potential Energy

1. Skate Boarder potential energy (PE) at the
top to kinetic energy (KE) going down and back to
potential energy (PE) at the top of the half-pipe
2. Model Airplane the wound rubber band has
elastic potential energy (PE) changed to kinetic
energy (KE) when it is released
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Ch.9, Sec.2 Energy Conversions

• Conversions Involving Chemical Energy

1. Chemical energy (CE) comes from food to help
us function
2. Light (LE) used by plants in photosynthesis to
make sugars (CE)
3. Conversions when you eat food light energy
(LE)--gt chemical energy (CE)--gtkinetic energy
(KE)
4. Conversions in a campfire light energy
(LE)--gtchemical energy (CE)--gtthermal energy
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Ch.9, Sec.2 Energy Conversions

• Why Energy Conversions Are Important

1. Conversions are needed for everything we do
2. Machines help us make energy conversions
3. Electrical energy can be converted into light,
sound, thermal, or kinetic energy!

• Energy Machines

1. A machine changes the size and the direction
of a force
2. Machines convert energy from one form to
another
3. Energy conversions in a bicycle chemical
energy (CE) to kinetic energy (KE)
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Ch.9, Sec.2 Energy Conversions
4. Bicycles seem easier to ride when kinetic
energy (KE) is transferred to the pedals, to
gears, to chain and back to the wheel
5. Radiometer turns light energy (LE) to
thermal energy (TE) to kinetic energy (KE)
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Ch.9, Sec.2 Energy Conversions

• Use your textbook (pgs. 248 253) to help you
  find all of the energy conversions for each
  example listed below

skateboarder _______________________________ mo
del airplane ______________________________ soc
cer player _______________________________ hair
dryer __________________________________ bicyc
le ____________________________________ radiome
ter _________________________________