How Guns Work
.... it. The increase in pressure
caused by the gases causes the bullet to be forced into the barrel hence causing
the bullet to come out the muzzle at very high speeds. Once the bullet is fired,
it remains in motion from its momentum. The momentum will carry the bullet
until it strikes an object or gravity pulls the bullet towards the earth.
Firearms change potential chemical energy into kinetic energy in the actual
firing of the gun. Many people do not realise that the force imparted by
accelerating the bullet is not the only force acting on the gun, or the shooter.
Grains of burned gun powder are sent out the muzzle at high ve .....
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Holograms
.... one side. The apple seems to "move" out of the way so you can
see the orange or even the back of the apple. If that seems a bit
obvious, just try looking behind something in a regular photograph!
You can't, because the photograph can't reproduce the infinitely complicated
waves of light reflected by objects; the lens of a camera can only focus those
waves into a flat, 2-D image. But a hologram can capture a 3-D image so
lifelike that you can look around the image of the apple to an orange in the
background -and it's all thanks to the special kind of light waves produced
by a laser.
.....
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Internal Combustion Engines
.... engine. This article emphasizes the spark-ignition engine.
The invention and early development of internal-combustion engines are
usually credited to three Germans. Nikolaus Otto patented and built (1876) the
first such engine; Karl Benz built the first automobile to be powered by such an
engine (1885); and Gottlieb Daimler designed the first high-speed internal-
combustion engine (1885) and carburetor. Rudolf Diesel invented a successful
compression-ignition engine (the diesel engine) in 1892.
The operation of the internal-combustion reciprocating engine employs
either a four-stroke cycle or a two-stroke cycle. A st .....
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Lasers And Their Uses
.... photon may
then strike other excited atoms, stimulating further emission of photons, all
of the same frequency and phase. This process produces a sudden burst of
coherent radiation as all the atoms discharge in a rapid chain reaction. The
light beam produces is usually pencil thin and maintains its size and direction
over very long distances.
Lasers vary greatly in the way they look and what they are used for.
Some lasers are as large as buildings while others can be the size of a grain
of salt.
There are many parts to lasers. I will now explain what they are and
their uses.
1) Pumping systems:
The pumping syst .....
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Radio: A Form Of Communication
.... (produce) a current
in another wire that was not physically connected to the first.
Hans Christian Oersted had shown in 1820 that a current flowing in a wire sets
up a magnetic field around the wire. If the current is made to change and, in
particular, made to alternate (flow back and forth), the building up and
collapsing of the associated magnetic field induces a current in another
conductor placed in this changing magnetic field. This principle of
electromagnetic induction is well known in the application of transformers,
where an iron core is used to link the magnetic field of the first wire or coil
with a secondary coil. By .....
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Steam Turbines
.... on which high pressure
steam is exerted. Stationary blades shift the steam onto rotating blades, which
provide power. Also, turbines are equipped with wheels or drums where the
blades are mounted. A shaft for these wheels or drums is also a basic component,
as well as an outer casing that confines the steam to the area of the turbine
proper. In order to efficiently use this contraption, it is necessary to have a
number of stages. In each of these stages, a small amount of thermal energy is
converted to kinetic energy. If the entire conversion of energy took place at
once, the rotative speed of the turbine wheel would be way t .....
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The Telephone
.... had a enormous advantage over the rest. And in a time as
economically troubled as the 30's depression, everyone was looking for a
competitive edge.
The telephone wasn't invented in the thirties, nor was the first
transatlantic line built then, but the thirties represents a time in history
when the world was changing incredible fast and much of that change was made
possible by the the telephone. Without the telephone, progress would have been
much slower and people might not have been so receptive to change. We owe a
great deal to Alexander Graham Bell, the inventor of the telephone, for his
invention has served mankind well a .....
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How Technology Effects Modern America
.... facts, I wonder if these trends are good or bad for society. “
The danger of the information age is that while in the short run it may be
cheaper to replace workers with technology, in the long run it is potentially
self-destructive because there will not be enough purchasing power to grow the
economy,” M. B. Zuckerman. My feeling is that the trend from unskilled labor
to highly technical, skilled labor is a good one! But, political action must
be taken to ensure that this societal evolution is beneficial to all of us. “
Back in 1970, a high school diploma could still be a ticket to the middle
income bracket, a nice car in t .....
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Internet Access
.... with Internet software on a personal computer. Terminal access
is usually done by a telephone line and a modem and it is used with terminal-
emulation software on a personal computer. This also allows you to interact
with another computer that is an Internet host (explained later). Gateway
access is similar to terminal access, but it is provided through on-line or
similar services or other networks such as Bitnet, Fidonets, or UUCP nets that
allow users to minimally exchange e-mail with the Internet.
The Internet is made by using different kinds of electronic transport
media including optical fiber, telephone lines, sa .....
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Dispute Over Computers And Knowledge To Operate Them
.... is involve to operate them.
O
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Machines: Are They Helpful Or Too Much Trouble?
.... they were very obedient and men
started giving them more respect.
Along with positive, were also negative. Most people worked twelve to
fourteen hours a day, six days a week, they had to pay constant attention to the
machines and risked losing limbs in the machines. Child labor was another
problem, they usually worked from 6 am to 7 p.m., getting paid only 10 percent
wages of men to children. They would be severely beaten, and usually was
deformed from machines. Many working-class children were not able to attend
schools, because they couldn't afford clothes. Women usually spent long hours
away from home and were unable to t .....
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Problems Of Modernization In Developing Nations
.... if one is removed, the other will fall.
Without resources to use, industry would not be able to maintain its existence.
Likewise, without a market for their resources, or the products of industry, the
developing world would not be able to maintain its existence.
Two current problems which exist in the developing world today are political
instability, and rapid urbanization. Political instability causes economic
problems in places such as Africa, and South America, where many governments are
being overthrown. When a government is inconsistent, a tax system cannot be
established and revenue can't be collected. If a government .....
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