Have you ever wondered how a jet aircraft lifts its
tremendous weight off the ground, or what gives a runner the
stamina to reach the finish line in a race? In order to answer
all these questions we must talk about the transformation of one
sort of energy into another.
The jet aircraft gets its power from jet turbines. These
powerful jet engines create a high-pressure stream of very hot
gases that push the aircraft forward as they leave the engine.
This is an example of heat being transformed into movement. This
is sometimes described as Mechanical Energy. However, this
transformation could not take place without the fuel that the
aircraft gets within its wings or fuselage. Fuel is considered a
chemical energy.
Fuel can take the form of gases, solids or liquids. When
fuels combine with oxygen from the air, they release their stored
energy as heat. We recognize this process as burning. The
individual relies on food for fuel which contains energy-giving
substances that our bodies can store until we need this energy to
use our muscles. When we do use our muscles within us, we may
not always be sure that heat is given off. Our bodies do not
burst into flames but the perspiration on our skin is a clue to
what is happening.
The movement of the windsurfer has a different explanation.
The windsurfer is propelled along by a sail which collects
mechanical energy from the winds that sweep along the water.
This energy has been produced by the sun which warms the earth’s
surface and sets the air above in motion. The sun’s heat comes
to the earth as a form of radiant energy. When the heat reaches
the surface of the earth, it causes the land or seas to rise in
temperature.
The sun is very hot. Infact, the center of the sun can
reach temperatures of up to 27 million degrees Fahrenheit. This
is because of another kind of energy reaction where new
substances are continually being created as others are being
destroyed. This reaction is known to us as the Nuclear Reaction.
Today we are trying to imitate this reaction in improving our
energy supply. Scientists have calculated that the sun has
enough fuel to go on producing energy at its present rate for
about five billion years.
On earth man-made nuclear reactions are used to produce a
form of power we know as electricity. Electricity can be
transformed into other kinds of energy such as heat, light and
radio waves. Humans have also used the idea of nuclear reactions
as a type of weapon. We call this powerful weapon the Atomic
Bomb. Electrical energy can also be used to produce laser beams.
This involves energy being concentrated to a specific narrow
point where the impact of so much power creates heat able to cut
through metals.
Bibliography
Discovering Energy, Frazer, Frank Trewin Copplestone Books Ltd,
1981.
Encyclopedia Britannica, Vol. 6 Encyclopedia Britannica, 1979.