Transcript Energy and Energy Resources

Energy and Energy Resources
Carin Miranda
Smyrna Middle School
Fall 2009
What is Energy?
• Energy is the ability to do work.
• Energy is expressed in joules (J).
Kinetic Energy
• Kinetic Energy is the energy of motion.
• Kinetic Energy = mv2 / 2
Potential Energy
• The Energy an object has based on shape or
position.
• Elastic potential energy
– When you change the shape of something
• Gravitational potential energy
– The higher something is off the ground the higher its
potential energy. The more it weighs the higher its
potential energy as well. Depends on height and
weight.
• Chemical potential energy
– The food you eat is stored as chemical potential energy
Mechanical Energy
• Is the total amount of energy in a system.
• Mechanical energy= potential energy + kinetic energy
• As kinetic energy goes up potential goes
down and vice verse.
Other Forms of Energy
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Thermal
Chemical
Electrical
Sound
Light
Nuclear
Thermal Energy
• Heat
• Higher the temperature the faster the
molecules move
• The more you have of a substance the more
thermal energy you have.
Chemical Energy
• Food you eat
• Batteries
• Anytime you have something breaking
down and it creates a new object.
Electrical Energy
• Moving electrons
• Anything you plug in.
• Batteries start as chemical energy but it is
converted into electrical energy.
Sound energy
• Caused by an objects vibrations
• Anything you hear
Light Energy
• Vibrations of electrically charged particles
• Anything you see.
• Waves that you can’t see
– Radio, Gamma, ultraviolet, microwaves
Nuclear Energy
• When two atoms fuse together(fusion) or
split apart (fission)
• Fusion happens in the sun
• Fission happens when uranium is split to
produce electrical energy
Energy Conversions
• A change from one form of energy to
another.
• Any form of energy can be converted into
any other form of energy.
Energy Conversions in Plants
• The nuclear energy of the sun produces
light and thermal energy.
• The light energy from the sun is converted
by plants into chemical energy which is
stored in the foods we eat.
Conservation of Energy
• Roller Coaster- Highest potential energy is
at the top of the biggest hill. Highest kinetic
energy is at the bottom of the biggest hill.
Law of Conservation of Energy
• Energy can never be created nor destroyed.
• It can only be transferred or converted.
• In every energy conversion some thermal
energy is given off due to friction.
• This means that there is no such thing as a
perpetual motion machine.
Energy Efficient?
• The amount of energy available before a
conversion compared to the amount of
useful energy after a conversion.
Energy Resources
• A natural resource that can be converted
into other forms of energy
• Nonrenewable
– Cannot be replaced or are replaced at a slower
rate than we are using it.
• Renewable
– Can easily be replaced.
Nonrenewable Resources
Fossil Fuels
• Includes coal, natural gas, petroleum.
• Most coal is used to generate electrical
energy.
Nuclear Energy
Uranium 1 uranium= 1 metric ton of coal.
Renewable
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Solar
Water (Hydroelectric)
Wind
Geothermal (hot water under ground)
Biomass (trash)
Advantages vs. Disadvantages
Know all the advantages and
Disadvantages of the Energy
Resources on Page 368