energy

• law of conservation of energy

  energy can be transferred usefully, stored or dissipated but cannot be destroyed or created
• reducing unwanted energy transfers

  • use a lubricant
  • remove the air particles from around the pendulum
• pendulum

  
• bungee jump

  • the jumper never returns back to its original position because energy is dissipated as thermal energy
  • friction with air particles
  • stretching effects in the rope which is not fully elastic
• fossil fuels

  • coal
  • oil
  • gas
• advantages of fossil fuels

  • reliable (always provide energy)
  • releases a great deal of energy
  • abundant and relatively cheap
  • versatile
• disadvantages of fossil fuels

  • release of carbon dioxide
  • non-renewable
  • release of other pollutants
• advantages of nuclear power

  • reliable
  • doesn't release carbon dioxide
• disadvantages of nuclear power

  • contains highly dangerous radioactive material
  • dismantling it can be expensive
  • radioactive waste has to be stored for 1000 years before it's safe
• switch from gas to coal

  • less carbon dioxide released
  • gas fired power stations are flexible
• advantages of renewable energy resources

  • never run out
  • does not add co2
• disadvantages of renewable energy resources

  • wind and solar power is unreliable
  • hydroelectric power is only suitable for countries with rivers and also destroys habitats
• biofuel

  • doesn't release extra c02 (carbon neutral)
  • produced from plant materials
  • used to power vehicles
  • may push up the price of food