SP3

• Types of energy stores

  1. Thermal
  2. Kinetic
  3. Nuclear
  4. GPE
• Law of conservation of energy


  Energy cannot be created or destroyed

  ~Energy is measured in Joules
• What is a closed system?


  A closed system is a system that does not exchange matter or energy with its surroundings.
• Four types of energy transfers

  1. Mechanically e.g. pushing
  2. Electrically e.g. charges
  3. By heating
  4. By radiation e.g. sun
• How to work out total energy input?


  Useful energy output + wasted energy
• Efficiency


  useful energy transferred/ total energy input
• How insulation in your house helps?


  -Cavity walls- create an air gap which reduces amount of energy

  -Loft insulation- good insulator reduces loss by conduction

  -Double glazed windows-air gap
• Non-renewable resources


  Will run out one day, finite
• Three main fossil fuels

  1. Coal
  2. Oil
  3. Natural gas
• Renewable resources


  Will never run out
• Examples of renewable resources

  1. The sun
  2. Wind
  3. Hydro-electricity
  4. Bio-fuel
  5. Tides
• Renewable resources- solar cells

  Solar cells

  -Use energy transferred by light to create electrical currant

  -Depends on country also no power at night
• Renewable resources- wind power

  Wind power

  -Has generator inside

  -Only work when it is windy
• Renewable resources-bio-fuels

  Bio-fuels

  -Made from plants and waste

  -Not enough space for crops to grow that are food
• Renewable resources- hydro-electricity

  Hydro-electricity

  -Involves flooding a valley by building dam

  -Impact on environment
• Renewable resources- tidal barrages

  Tidal barrages

  -Big dams with turbines in them

  -Affect boat access and alter habitat
• Advantages of non-renewable resources


  -Reliable

  -Cost effective
• Disadvantages of non-renewable resources


  -CO2 emissions

  -They will run out

  -Environmental issues from extraction
• 3 ways heat transfers

  1. Conduction
  2. Convection
  3. Radiation
• Conduction


  Vibrations passed from particle to particle in a solid

  -Best conductor because of strong structures
• Best conductors


  -Solid

  -Liquids
• Best insulators


  -Vacuum

  -Gases
• Convection


  Movement of particles in a fluid depending on their temperature
• Convection current


  The way that heat is transferred throughout a fluid
• Radiation


  Transferring energy by heating
• What are heat rays?


  Infra red radiation
• Facts about radiation


  -Black is the best absorber and emitter

  -Lighter surfaces are best at reflecting and worst at emitting