Download PowerPoint for Energy Transformations

Energy Transformations
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Changing Forms of Energy
•
•
Chemical, thermal, radiant, and
electrical are some of the forms that
energy can have.
In the world around you, energy is
transforming continually between
one form and another.
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Tracking Energy Transformations
•Because of friction,
the mechanical
parts of the bicycle
are warmer, too.
The energy transformations
that occur when people
•Thermal
energy
is
exercise, when cars run, when
almost
living things grow and
even always
produced
by an
when stars explode,
all
produce thermal energy.
energy
transformation.
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Potential energy is converted into kinetic energy.
•A waterfall has both
potential and kinetic
energy. The water at
the top of Bridal Veil
Falls has stored
potential energy. At
what point does the
water have the most
potential energy? The
most kinetic?
Roughly equal?
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Potential energy is converted into kinetic energy.
• Think about the energy
transformation when
you want to
demonstrate your mad
YoYo skillz.
• Where did the energy
come from? Where does
it go?
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Energy Changes Form
• A car engine burns
gasoline, converting
the chemical energy in
gasoline into
mechanical energy.
Solar cells change
radiant energy into
electrical energy.
Energy changes form,
but the total amount of
energy in the universe
stays the same.
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Energy Changes Form
 You wake up. It's a cool, sunny day,
You think you'll go for a bike ride. But
first you eat a good healthy breakfast.
What kind of energy are you taking in?
 Without your needing to think about it,
the cells in your body will break down
the chemical bonds in the food and
release the energy in those bonds
when you need it. You'll use the
energy to stay warm, to grow, to keep
your internal organs working, and to
move your muscles.
 What energy transformations occur
when you ride a bike?
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Energy Changes Form
And you are moving. You
jump up from the table,
grab a jacket, head out
the door. You hop on
your bicycle.
The energy of motion is
called kinetic energy. As
you pump your legs, the
bicycle starts to roll. Your
kinetic energy is being
transferred to the bicycle.
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Energy Changes Form
Back at home, you turn on a radio. It runs on _______ energy
which travels along the wires that connect a power plant to your
home. The
?
energy used by the radio is converted into
?
energy.
Sound is another form of ? energy--it's air in motion. You
can move your muscles to make sound too. For example, you
can hit a drum, sing or shout, or strum on a guitar. The guitar
strings, vocal cords, or drumhead, once set in motion, make the
air around them move, transforming the energy to _________
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Transforming Electrical Energy
• Every day you use
electrical energy.
When you flip a
switch, or turn on a
radio or television,
or use a hair drier,
you are
transforming
electrical energy to
other forms of
energy.
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Changing Forms of Energy
• Forest fires are a dramatic example of
an environmental change that can
occur naturally as a result of lightning
strikes.
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Tracking Energy Transformations
•As the mountain
biker pedals, his leg
muscles transform
chemical energy
into kinetic energy,
applied to the
pedals of the bike.
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Tracking Energy Transformations
•Some of the bike’s
kinetic energy
transforms into _____
energy as it moves up
the hill.
•The biker’s body is
warmer because
_____ energy is
being transformed
into ________ energy.
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Tracking Energy Transformations
•Because of friction,
the mechanical
parts of the bicycle
are warmer, too.
•What energy
transformation
occurs?
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Law of Conservation of Energy
• Energy is never created or destroyed.
• The only thing that changes is the form in
which energy appears.
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Generating Electrical Energy
Every Power plant works on the same principle--energy is used to turn a large generator. A
generator is a devise that transforms kinetic energy
into electrical energy. In fossil fuel power plants,
coal, oil, or natural gas is burned to boil water. As
the hot water boils, the steam rushes through a
turbine, which contains a set of narrowly spaced fan
blades. The steam pushes on the blades and turns
the turbine, which in turn rotates a shaft in the
generator to produce the electrical energy.
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Power Plants
Almost 90 percent of the electrical energy
generated in the U.S. is produced by nuclear
and fossil fuel power plants. Other types of
power plants include Hydroelectric and wind.
Hydroelectric power plants transform the
kinetic energy of moving water into electrical
energy. Wind power plants transform the
kinetic energy of moving air into electrical
Sources of Electrical Energy in the U.S.
energy.
20%
Coal
Oil
3%
Gas
51%
9%
Hydro
Other Renewable
14%
Nuclear
3%
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