Energy



  • The word energy comes from the Greek word energeia.

  • Most types of energy are either a form of kinetic energy or potential energy.

  • Common examples include heat energy, elastic potential energy, chemical energy,
    sound energy, nuclear energy,geothermal energy and gravitational potential energy.

  • Kinetic energy refers to the energy an object has because of its movement.
    A car in motion has kinetic energy, as does a basketball when you pass or shoot it.

  • Energy can be transformed from one form to another. In lightning, electric
    potential energy transforms into,heat and sound energy.

  • The law of conservation of energy states that energy can only be transformed,
    it can’t be created or destroyed.

  • You might have heard of Albert Einstein’s famous formula E = mc²
    (energy equals mass multiplied by the speed of light squared).

  • Food contains chemical energy which is used by living organisms such as
     animals to grow and reproduce. Food energy is usually measured in calories or joules.

  • Wind farms contain large numbers of wind turbines which are used to
    transform wind energy into a useful energy such as electricity.
    The use of wind power to generate electricity doubled between the
    years 2005 and 2008.

  • The USA's Mojave Desert is home to the world's largest solar power plant.

  • The Three Gorges Dam in China is the world's largest hydroelectric power station.

  • Nuclear power produces around 13% of the world's electricity.

  • Plants use energy from sunlight during an important process called photosynthesis.

  • A person standing on a diving board above a swimming pool has
     gravitational potential energy.

  • During chemical reactions, chemical energy is often transformed
     into light or heat.

  • Stretched rubber bands and compressed springs are examples of  elastic potential energy.