Energy transfers

• What is a system

  • object or group of objects
  • when there is a change in a system, energy is transferred
• what is an open system

  • Allows the exchange of energy and matter to/from its surroundings
• what is a closed system

  • Can exchange energy but not to/from its surroundings
• what is an isolated system?

  Does not allow transfer of matter or energy to/from its surroundings
• what is the law of conservation of energy?

  • Energy cannot be created or destroyed, only transferred
• what is kinetic energy

  moving objects
• what is gravitational energy

  objects gain this when they move through a gravitational field
• what is elastic energy

  if they are stretched, squashed or bent
• what is magnetic energy

  magnetic materials which interact with eachother
• what is chemical energy

  chemical reactions transfer energy to/from a substances chemical store
• what is thermal energy

  all objects have thermal store

  hotter objects = higher thermal store
• what are transfer pathways

  • Energy is transferred between stores via transfer pathways
  • mechanically
  • electrically
  • heating
  • radiation
• what is mechanical working

  • a force acts on an object
• what is electrical working

  A charge moves through a potential difference