Energy

many small children seem to have an endles supply of energy.this ussually leaves their parents feeling in turn that they have very little energy!.Our bodies need a constand supply of energy from the food we eat in order to work properly.Diferent forms of energy is constantly being changed form one form into an other.
Energy all around us:
Chemical energy:
they are burned to produce that energy.natural ga(methane)and other fuels contain it.
Electrical energy:is used to provide movement.
Sonud and light energy:
1.SOUND:
Sound waves require some kind of material to travel through. They can't move through a vacuum.
Sound waves move much much slower. Their speed in air is about 330 metres per second.
Sound waves are like heat conduction. No particles actually travel.

2.LIGHT:
Light waves don't require a material to travel through. They can move through a vacuum.
Light waves move very very fast. The speed of light is about 300,000 kilometres per second.
Light waves are like little particles that actually move from place to place.

Nuclear energy:
The sun and stars are seemingly inexhaustible sources of energy. That energy is the result of nuclear reactions, in which matter is converted to energy. We have been able to harness that mechanism and regularly use it to generate power. Presently, nuclear energy provides for approximately 16% of the world's electricity. Unlike the stars, the nuclear reactors that we have today work on the principle of nuclear fission. Scientists are working like madmen to make fusion reactors which have the potential of providing more energy with fewer disadvantages than fission reactors.