Energy transfer

• Energy is the ability/ capacity to do work. Work is said to be done when a force moves an object a distance
• The SI unit for energy is the joule (J)
• The instrument used for measuring energy is called a joulemeter
• Energy stores

  • Chemical energy
  • Gravitational potential energy
  • Elastic potential energy
  • Thermal energy
  • Atomic energy
• Transfer mechanisms

  • Electric energy
  • Kinetic energy
  • Solar energy
  • Light energy
  • Sound energy
• Electric energy: transfered by the movement of charged particles
• Chemical energy: found in foods, fuels, feeds & batteries
• Gravitational potential energy (GPE): energy due to height from a given point.

  
  

  GPE is given by: GPE= mass x gravitational field strength x height
• Elastic potential energy: is energy stored in elastic materials and compressed springs
• Kinetic energy: is energy in moving bodies

  
  

  KE is given by: KE= 1/2 x mass x speedxspeed
• Solar energy: it is energy from the Sun. It is form of light and heat energy
• Light energy: energy that we can detect with our eyes and helps us see
• Sound energy: energy caused vibrating objects
• Thermal energy: energy that raises the temperature of a body
• Atomic energy: energy found in the nucleus of an atom
• There are 4 transfer mechanisms:

  • By heating- here chemical energy in fuel is burnt to transfer it into thermal energy store
  • By radiation- this transfer .e.g through sound, light
  • Electrically- where charge flow to transfer energy. This occurs in good electrical conductors
  • Mechanically- where work is done to move an object a distance
• Internal energy: is the sum of molecular potential energy
• Transducer: is a device that converts one form of energy into another form of energy.
• Law of conservation of energy:

  It states that energy can not be created or destroyed but can be transfered.