How a Kite is Flying – Example Of
Explanation Text
A kite is an object which is made from a light
material stretched over a frame. Due to its light material a kite will lift off
the ground and fly when it is tilted into the wind.
A kite is uses wind to make it fly because it is heavier than air.
When wind travels over the surface of the kite, it is split into two streams of
air. One stream of the air goes over the kite while the second stream goes
under the kite.
The upper stream creates an area of low pressure above
the kite. The lower stream hits the kite at a shallow angle and creates an area
of high pressure.
The high pressure area has a pushing effect while the
low pressure area has a pulling effect. The combination of push and pull can
creates enough force to lift the kite into the air.
Kites have been known for thousand of years. They are used for
military or scientific purposes. Todays kites are much used for leisure and
competition.
How Roman Roads were Built- Example
of Explanation Text
The system
of roads for mobility has been begun early decades. It was started since the
Roman Empire conquered the world. The roads in Roman era were known as the best
construction.
The Romans
built roads are for the purpose of mobility, especially for the army. Having
the best road, the army could march from one place to another. They built the
roads as straight as possible, so that the army could take the shortest route.
It is
interesting to know how the roads were built, which some of them are still in
use today. First, the Romans builders would clear the ground of rocks and
trees. Then they dug a trench where the road was to go and filled it with big
stones. Next, they put in big stones, pebbles, cement and sand which they
packed down to make a firm base. After that, they added another layer of cement
mixed with broken tiles. On top of that rough construction, then they put
paving stones to make the flat surface. These stones were cut so that they
fitted together tightly. As the finishing touch, kerb stones were put at each
sides of the road to hold in the paving stones. It was also used to make a
channel for the water to run away.
Example of Explanation Text -
Cancer
What is cancer? It is actually a group of more than
one hundred separate diseases. Most of us are fear from cancer It is reasonable
because next to heart disease, cancer is the second leading cause of death.
Cancer cells come from normal cells because of
mutations of DNA. Those mutations can occur spontaneously. The mutations may be
also induced by other factors such as: nuclear and electromagnetic radiation,
viruses, bacteria and fungi, parasites, heat, chemicals in the air, water and
food, mechanical cell-level injury, free radicals, evolution and ageing of DNA,
etc. All such factors can produce mutations that may start cancer.
Cancer cells are formed continuously in the organism. It is estimated that
there are about 10,000 cancer cells at any given time in a healthy person. Why
do some result in macroscopic-level cancers and some do not? First, not all
damaged cells can multiply and many of them die quickly. Second, those which
potentially divide and form cancer are effectively destroyed by the mechanisms
available to the immune system. Therefore cancer develops if the immune system
is not working properly or the amount of cells produced is too great for the
immune system to eliminate.
How Fuel Light Works; Example Of
Explanation Text
Many cars, motorcycles and other modern vehicles have
fuel warning light devices. the warning light is usually red which switches on
automatically when the level of fuel in the tank is very low. The warning light
gives the driver information about the amount of petrol in the tank. When the
light switches on red, it tells the driver that the petrol in the tank is
almost empty. Therefore he have to put more fuel into the tank. However do you
know how the fuel warning works?
Well this is the way the fuel warning light work and
gives the driver information about the accurate amount of the petrol in the
tank. When the level of the fuel falls, the float inside the tank moves
downwards. When this condition happens, the arm also moves downwards and it
make the lever touch an electrical contact. This switches on the fuel light in
the car dashboard.
The red light which appears in the fuel panel of the dashboard tells the driver
that he needs more petrol for his car. When he pours more petrol into the tank,
this condition makes the fuel level rise and it pushes the float upwards. In
return it disconnects to the electrical contact and makes the red light switch
off.
Tsunami – Example of Explanation Text
The term of
“tsunami” comes from the Japanese which means harbour (“tsu”) and wave
(“nami”). A tsunami is a series of waves generated when water in a lake or a
sea is rapidly displaced on a massive scale.
A tsunami
can be generated when the sea floor abruptly deforms and vertically displaces
the overlying water. Such large vertical movements of the earth’s crust can
occur at plate boundaries.
Subduction
of earthquakes are particularly effective in generating tsunami, and occur
where denser oceanic plates slip under continental plates.
As the
displaced water mass moves under the influence of gravity to regain its
equilibrium, it radiates across the ocean like ripples on a pond.
Tsunami
always bring great damage. Most of the damage is caused by the huge mass of
water behind the initial wave front, as the height of the sea keeps rising fast
and floods powerfully into the coastal area.
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