conservation and dissipation of energy

• A system is an object or group of objects
• A closed system is one where no energy can escape to or enter from the surroundings.
• The total energy in a closed system never changes.
• Whenever anything changes in a system, energy is transferred between its stores or to the surroundings.
• kinetic energy

  energy an object has because it is moving
• gravitational potential

  energy an object has because of its height above the ground
• elastic potential

  energy an elastic object has when it is stretched or compressed
• thermal (or internal)

  energy an object has because of its temperature
• chemical

  energy that can be transferred by chemical reactions involving foods, fuels, and the chemicals in batteries
• nuclear

  energy stored in the nucleus of an atom
• magnetic


  energy a magnetic object has when it is near a magnet or in a magnetic field
• electrostatic

  energy a charged object has when near another charged object
• Heating

  Energy is transferred from one object to another object with a lower temperature.
• Waves

  Waves (e.g., light and sound) can transfer energy.
• Electricity

  An electric current transfers energy
• Forces (mechanical work)

  Energy is transferred when a force moves or changes the shape of an object.