Energy Basics

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Energy Basics
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Energy

• The ability to do work or cause change
• Either potential or kinetic

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Potential Energy

• Energy that is stored. The snow on the mountain
  top represents potential energy.

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Potential Energy

• Potential energy is highest when the object is at
  a higher point, like this roller coaster on the
  top of a hill. The higher the hill the greater
  the potential energy.

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Potential Energy

• The more mass something has the greater its
  potential energy. In the picture below the man
  holding the weight above his head is holding a
  lot of potential energy.

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Kinetic Energy

• The energy of motion

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Kinetic Energy

• The faster the motion the greater the kinetic
  energy. When the roller coaster starts down the
  hill it has kinetic energy. The point where the
  car is going the fastest is where the kinetic
  energy is the greatest.

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Forms of Energy

• Energy can be found in many forms
• Can be converted from one form or another
• Conversion can be both man made and a natural
  process
• Forms include chemical, thermal, elastic,
  radiant, mechanical and nuclear.

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Chemical Energy

• Stored in chemical bonds holding the atoms of
  compounds together
• Food, wood, batteries, fossil fuels

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Chemical Energy

• When a chemical reaction takes place energy is
  used.
• If energy is pulled in from the surrounding area
  during a chemical reaction, the area gets cold
  and the reaction is endothermic.
• Commercial ice packs for injuries work this way.

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Chemical Energy

• When a chemical reaction takes place and releases
  energy it can increase the temperature. We call
  this an exothermic reaction.

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Chemical Energy

• Plants can make their own energy through a
  process called photosynthesis. They are the bases
  for a food chain. All other living things that
  cannot carry on photosynthesis depend on plants
  for their energy.

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Energy Transformation

• In photosynthesis radiant or light energy from
  the sun is changed to chemical energy in the leaf.

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Chemical Energy

• Other living things can get energy from eating
  plants or eating things that eat plants.

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Chemical Energy

• The energy we eat is stored as potential chemical
  energy until we need it. When we use the energy
  through an activity then it becomes kinetic
  mechanical energy.

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Chemical Energy

• Plants make food through the process of
  photosynthesis. When we use the energy from the
  chemical energy we store we break it down through
  a process called respiration. These are opposite
  energy reactions.

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Electrical Energy

• Energy of moving electrons
• Invisible but most useful
• form
• When the electrons are
• separated from positive
• charges and then forced
• along a closed path in
• a conduction material
• ex copper

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Energy Transformation

• Electrical energy can come from many different
  sources. The sources can be solar, nuclear,
  mechanical or generally chemical. In Texas most
  of our electricity comes from the burning of the
  coal, lignite. The energy transformation that
  takes place would be
• Lignite (chemical)-gtmoving turbines
  (mechanical)-gtmoving electrons (electrical)-gt our
  homes

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Mechanical Energy

• Most familiar-involved with moving objects atoms
  are moving and pushing each other
• Sound is an example-occurs when atoms in a media
  vibrate in a direction outward from the sound
  source. Sometimes, sound is classified as its own
  energy source.

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Mechanical Energy

• When we move or work we are using mechanical
  energy.

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Energy Transformations

• Automobiles use chemical energy (fossil fuels)
  which is converted to mechanical energy when they
  move.

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Radiant or Light Energy

• Produced when atoms absorb energy from an outside
  source and release energy as electromagnetic
  radiation
• Most are invisible except for visible light
• UV rays, X-rays, radio waves

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Radiant or Light Energy

• Our ultimate energy source is radiant energy from
  the sun.

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Radiant or Light Energy

• In a light stick you have chemical energy stored
  in the vial. When you bend the stick and break it
  then light energy is released.

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Radiant or Light Energy

• We use light energy in our homes.
• Many people have switched to compact fluorescent
  light bulbs over other light bulbs (incandescent)
  because they do not put out as much heat (thermal
  energy). The compact florescent bulbs are more
  energy efficient so they help in energy
  conservation.

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Thermal Energy

• A special form of kinetic energy
• Energy of moving or vibrating molecules
• The faster the molecules vibrate the hotter they
  become
• When heat is produced we have thermal energy.

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Thermal Energy

• Volcanoes can be a natural source of thermal
  energy. When we use the heat of the earth it is
  called geothermal energy.

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Elastic Energy

• Energy stored in a solid object when it is either
  stretched or compressed.
• A stretched rubber band, compressed spring or
  jack-in-the-box

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Nuclear Energy

• Energy stored in the nuclei of atoms
• Released by fission, the splitting of nuclei of
  heavy atoms
• Released by fusion-the combining of nuclei of
  light atoms

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Nuclear Energy

• Einstein predicted the energy in a nuclear
  reaction before we had even split the atom in his
  famous equation
• E m c2
• Eenergy, m mass and c2 is the speed of light.
  He is basically saying if we take the mass of an
  object and multiply it by the speed of light that
  will tell us how much energy it contains. This
  did not make a lot of sense at the time.

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Nuclear Energy

• When the energy released from the splitting of an
  atom was discovered this made the equation make
  sense. There is an infinite amount of power in
  nuclear energy. This is what powers stars like
  our sun. Hydrogen is turned into helium. This
  process will continue until our sun runs out of
  hydrogen. This will be in about 4 billion years.

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Nuclear Energy

• We are trying to harvest the power of the atom
  when we use nuclear energy.

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Energy Basics

• There are many issues involved with energy.
• Renewable vs. Nonrenewable
• Energy Conservation
• Environmental Concerns
• Pollution
• These are just a few of the things you can study
  when studying energy.