Friday, January 11, 2013

HOW MACHINES FUNCTION


Machines need energy in order to function.
This energy comes from different sources:

  • People are the energy source for canoes and bicycles. 
  • Electricity is the energy source for refrigerators and computers. 
  • Combustible fuels are the energy source for cars and rockets. 
  • Wind is the energy source for windmills and sailing boats.

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