Rest Energy

Matter can be converted into energy, and energy into matter. The rest energy of a body is the energy it has by virtueof its mass alone. Therefore mass can be considered a form of energy. The rest energy of a body is in addition to any Kinetic energy or Potential Energy it might have also. If the mass of a body is m when it is at rest, its rest energy is : Rest energy= E=mc^2, where c =186000 mi/sec (speed of light)

History of Rest Energy

The theory of rest energy was discovered by Albert Einstein. It developed out of his theory of Relativity. Einstein believed that his dicoveries were more than just a clever exercise of the mind. During his time scientists had not believed that movement of matter could not alter its basic nature. Mass energy means that a body at rest must have energy.

Application of Rest Energy

One way that rest energy is used is to determine how much mass is converted to energy per day in a nuclear plant. It is also used to determine the amount of mass converted to energy in the sun each second. nuclearplant.jpg


  1. Beiser, A. (1988). Physical Science (2nd Edition). New York, NY: McGraw Hill
  3. Life Science Library ENERGY by Mitchell Wilson and editorsof Time Life Books 1963-1967
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