Transcript The Nature of Energy

The Nature of Energy
Section 4.1
Energy
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Every change that occurs involves
Moving objects have energy
You can tell an object has energy when it:
Changes its environment
 Changes itself
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Energy
Electrical – moving electrons
 Chemical – from bonds
 Thermal- heat
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Energy
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Energy exists in many different forms
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It may look different, but it’s still energy.
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Examples: fire, movement, gasoline in a bucket
Kinetic energy- energy in the form of motion
Depends on mass and velocity of an object
 Increase in either mass or velocity = increase in
energy
 KE =1/2 mv2
 Units = kg*m/s
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Types of Energy
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KE = ½ mv2 Velocity changes will impact KE
more because velocity is squared.
Potential Energy – energy of position
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Energy in stationary objects and bonds
Elastic Potential Energy – Energy of
compression or stretching
Chemical Potential Energy – Energy stored in
bonds
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Gasoline, food, hand warmers
Types of Energy
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Gravitational Potential Energy- Energy stored
due to position above the surface of Earth
Depends on mass of object, height of object above
ground, and acceleration due to gravity
 GPE = m x h x g
g = acceleration due to gravity
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All energy – measured in units of Joules
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1 J = 1 kgm2/ s2
Energy can be converted:
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As an object falls, GPE decreases and KE increases