Energy

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Energy
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What is energy?

• Energy makes things happen
• For example energy makes sounds, allows objects
  to move and work, destroys things (like the
  tornado on the last page)
• The Law of Conservation of Energy states that
• Energy can not be created or destroyed, but it is
  changed from one form to another
• Why do we need replace batteries then?

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Forms of energy

• There are lots of different types of energy
• They are measured in Joules
• We need energy to move, this comes from food and
  food contains chemical energy
• This chemical energy also keeps our body
  temperature at 37Celcius
• Chemical energy can be changed into movement
  (kinetic) and heat energy

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Chemical Energy

• When we eat we put food (chemical energy) into us
  
• This energy can be stored as fat or used by our
  body
• Batteries also contain chemical energy
• Petrol, diesel, coal, wood and gas all have
  stored chemical energy

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Electrical Energy

• Electrical energy usually flows through wires
• Chemical energy from a battery is converted into
  electrical energy in the wires
• It can also occur as static e.g. lightning

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Gravitational Potential Energy

• At the top of this roller coaster the cars stop
  for a split second
• At this point they have Gravitational (potential)
  energy
• Gravity will pull the cars down again (they will
  have kinetic energy)

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Elastic Potential

• The string of the cross bow has elastic energy
  when it is pulled back
• When released this elastic energy is changed into
  kinetic and sound energy

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Kinetic Energy

• This is movement energy
• Our muscles produce the movement
• Car engines do the same
• When we move we produce heat

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Sound Energy

• Sound energy is created by
• objects hitting the ground with a thud
• arrows flying though the air with a woosh
• bullets fired from guns making a bang
• People taking
• Objects vibrating e.g. drum skins, guitar strings
  etc.

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Light Energy

• Light is the fastest form of energy known to man
• It takes 8 minutes to travel from the Sun to the
  Earth
• The suns energy is called Solar energy
• Light energy can be used by solar panels to make
  electricity

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Thermal Energy

• Thermal means heat
• All machines (and animals are machines to a
  scientist) are not perfect
• They waste chemical energy usually turning it
  into heat energy, this escapes into space (space
  is gradually getting a little warmer)
• When we run we convert chemical energy from food
  into movement energy, but we also get warm and
  this waste heat escapes into the air and then
  into space

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Energy Transfer

• Energy can be changed into different types e.g.
• A torch

Chemical energy
Light energy
Heat energy
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Non Renewable Energy

• Non renewable means cannot be renewed
• In other words this energy will run out
• Fossil fuels are the main sources of
  non-renewable energy
• These are
• Coal
• Oil
• Natural Gas
• Nuclear fuels are also non-renewable

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Renewable Energy

• These types of energy can be renewed
• This means that they can be used again and again
• Examples include
• Solar
• Hydroelectric
• Wind
• Tidal

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Solar Power

• Solar panels change light energy into electrical
• What are the advantages and disadvantages of this
  type of energy?

A Solar Farm
Solar Power Cars
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Wind Energy

• Wind turbines convert wind energy into electrical
  
• Why is there so much opposition to wind farms?

A Wind Farm in Palm Springs
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Hydroelectric Energy

• Potential energy of the water in the reservoir is
  converted kinetic energy in turbines then into
  electrical energy
• This is the Hoover dam in the USA

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Biomass

• This is living or decomposing matter that can be
  used for fuel e.g.
• Wood chips and branches
• Cars can be run on bio-fuels either alcohol
  (fermented from corn) or oil (vegetable oil)

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The Koenigsegg CCXR Edition runs on alcohol fuel
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Geothermal Energy

• The Earth is hot under the surface
• This heat can create geysers of hot water and it
  can be used to make electricity or heat homes

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New Technology

• Formula 1 cars have used the kinetic energy from
  braking to generate more electricity
• Modern electric cars also use this regenerative
  braking
• The Tesla Roadster is an electric car with this
  braking

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The Tesla Roadster