Mechanical Energy

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. This diagram shows
how the jet engine acts as energy to lift the aircraft
off the surface of earth. 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.

Category: Science