energy concepts 1.4

• efficiency


  useful energy transfer over total energy input x100
• force displacement graph


  area under graph = elastic potential energy
• law of conservation of energy

  energy can't be created or destroyed, only be transferred from one form to another, energy of system must remain constant
• power


  rate of transfer of energy
• kinetic energy 


  energy of an object due to its motion
• gravitational potential energy


  energy of an object due to its position above the surface of the earth
• elastic potential energy


  energy of an object due to it being deformed by a force
• work done 


  equal to the amount of energy transferred
• work


  when a force is applied to an object that moves, work is done by that force