energy transfers

• give types of energy transfer between energy stores

  heating, radiation and work done by forces and current flow
• describe conservation of energy

  energy cannot be destroyed or created but transferred usefully, stored or dissipated
• describe close system

  no net change to total energy
• describe dissipated / waste energy

  energy stored in non useful way
• describe conduction

  vibrating particles transfer energy to neighbouring particles
• describe thermal conductivity

  measure of how quickly thermal energy is transferred through a material via conduction
• describe convection

  energetic particles move away from hotter regions to cooler regions
• give methods to reduce energy transfer

  lubrication and thermal insulation
• describe lubrication

  reduce energy transfer by work done as friction force between moving objects
• give examples of thermal insulation

  cavity walls, double glazed windows, loft insulation and draught excluders
• describe affect of cavity walls and double glazed windows

  air gap between to reduce energy transfer through conduction
• describe affect of loft insulation and draught excluders

  reduce energy transfer by convection
• give factors affecting rate of cooling of building

  wall thickness and thermal conductivity
• give methods to increase efficiency of energy transfer

  lubrication, insulation and streamlined