Machines and energy

                                     

                       Machines and energy: different kinds of energy.

   

       Most machines that help us are moved by burning  fuels, e.g. a car, a bus and a 

plane, they need some kind of gasoline.   

      

      There are some others which move by simple pushing, such as the bike or the 

skates.  Some machines need energy from people to make them work, for example a 

a stapler, and a pair of scissors.  Other machines use electricity such as the hairdryer

and electric drill .  But we must be careful with electricity to be safe with 

it. Electricity flows through metals, water and people. These materials

are conductors.  Other materials such as plastic, glass and rubber block the flow of 

electricity and cover the conductors to protect us, remember the plugs convered by

plastic.They are insulators. 

   Nowadays, some machines use energy from the Sun (solar energy), wind and 

water. They produce very little pollution. 

Think about some objects at home to insulate you from electricity!