Forms of Energy

• Energy: the ability to do work.
• For an object to have kinetic energy, something must do work to it.
• Energy is measured in joules (J).
• Mechanical energy is the total energy an object has because of its motion (speed) or position.
• Mechanical energy = (stored) potential energy + kinetic energy.
• Types of Potential energy:

  • Gravitational - dependent on mass & height
  • Elastic - stored due to an object being stressed/compressed
  • Chemical - stored in bonds between atoms
  • Nuclear - stored in the nucleus of an atom, a highly concentrated form of energy
• Gravitational energy: dependent on mass & height.

  E.g. at the top of a roller coaster
• Elastic energy: stored due to an object being stressed/compressed.

  E.g. a rubber band being snapped.
• Chemical energy: stored in bonds between atoms.

  E.g. petrol, food.
• Nuclear energy: stored in the nucleus of an atom, a highly concentrated form of energy.

  E.g. nuclear explosions.
• Types of Kinetic energy:

  • Thermal - vibration & movement of molecules
  • Electrical - movement of electrons
  • Sound - vibrational movement through substances in waves
  • Radiant - energy carried by light waves
• Thermal energy: vibration & movement of molecules.

  E.g. pan heating up.
• Electrical energy: movement of electrons.

  E.g. lightbulb.
• Sound energy: vibrational movement through substances in waves.

  E.g. music.
• Radiant energy: (light) energy carried by light waves.

  E.g. the sun.