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CHAPTER NO 1
FOOT- POUND-SECOND SYSTEM OF UNITS
The foot-pound-second (fps) system of units is a scheme for measuring dimensional and
material quantities. The fundamental units are the foot for length, the pound for weight, and
the second for time.
The FPS system has two variants, known as the American version and the Imperial version.
Neither scheme is often used by scientists nowadays; the International System of Units (SI) is
preferred. However, fps units are used to some extent by the general public, especially in the
United States.
Foot One foot (1 ft) represents a length of 12 inches. The inch was originally defined as the
length of three typical barleycorns laid end-to-end. A foot was also approximately equal to
three hand widths or 2/3 of a cubit (the distance from an average person's elbow to the tips of
the fingers). Nowadays, a foot is considered to be 0.3048 meter, where the meter is the
fundamental unit of displacement in the metric system and International System of Units (SI).
Pound
One pound (1 lb) is the force that produces an acceleration of 32.1740 feet per second
squared (32.1740 ft/sec
2
) when applied against a known standard mass. The acceleration of
32.1740 ft/sec
2
is approximately the value of the earth's gravitational acceleration at 45
degrees north latitude.
Second
One second (1 s or 1 sec) is the time that elapses during 9.192631770 x 10
9
cycles of the
radiation produced by the transition between two levels of Cesium 133. It is also 1/86,400 of a
mean solar day. (There are 60 seconds in a minute, 60 minutes in an hour, and 24 hours in a
day; 60 x 60 x 24 = 86,400 s.)
CENTIMETER, GRAM AND SECOND SYSTEM
In 1954, the Tenth General Conference on Weights and Measures (CGPM) adopted the
meter, kilogram, second, ampere, degree Kelvin, and candela as the basic units for all
international weights and measures, and in 1960 the Eleventh General Conference adopted
the name International System of Units (SI) for this collection of units. (The "degree Kelvin"
became the kelvin in 1967.) In effect, these decisions gave the central core of the MKS
system preference over the CGS system. Although some of the CGS units remain in use for a
variety of purposes, they are being replaced gradually by the SI units selected from the MKS
system.

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CHAPTER NO 2
COMPOSITION OF WATER
Water was considered as an element before Priestly (1776). He explored a mixture of
hydrogen and oxygen to get water by using an electric spark. By using this experiment,
Priestly established that, water is a compound of hydrogen and oxygen and not an element.
DECOMPOSITION OF WATER
Later, experiments on the explosion of mixtures of hydrogen and oxygen revealed that,
in forming water, hydrogen and oxygen decomposition of water by an electric current
(electrolysis) confirmed that hydrogen and oxygen combined in the ratio of two parts of
hydrogen to one part of oxygen by volume. The apparatus used for this, known as
Hofmann’s voltammeter.
HYDROGEN
Hydrogen is one of the most important elements. It is also the lightest element and
has the simplest atomic structure. An atom of hydrogen contains one proton in the nucleus
and one electron in the first orbit. Hydrogen, therefore, has an atomic number of one and
occupies the first place in the periodic table. However, it is unique element t and does not fit
well into any of the group.
PREPARATON OF HYDRONGEN
There are two types of preparation of hydrogen.
1. Laboratory Preparation.
2. Chemical Preparation.
Laboratory preparation
In the laboratory, hydrogen can be prepared by the following methods:
a. By the reaction of certain metals with dilute mineral acids.
b. By the reaction of aluminum metal with a base.
c. By the reaction of calcium hydride with water.
Chemical Preparation.
Commercial hydrogen is relatively less pure and can be prepared by following
methods.
(1) By passing steam over red hot coke. It is very difficult to eliminate
CO completely from hydrogen.

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CHAPTER NO 1 FOOT- POUND-SECOND SYSTEM OF UNITS The foot-pound-second (fps) system of units is a scheme for measuring dimensional and material quantities. The fundamental units are the foot for length, the pound for weight, and the second for time. The FPS system has two variants, known as the American version and the Imperial version. Neither scheme is often used by scientists nowadays; the International System of Units (SI) is preferred. However, fps units are used to some extent by the general public, especially in the United States. Foot One foot (1 ft) represents a length of 12 inches. The inch was originally defined as the length of three typical barleycorns laid end-to-end. A foot was also approximately equal to three hand widths or 2/3 of a cubit (the distance from an average person's elbow to the tips of the fingers). Nowadays, a foot is considered to be 0.3048 meter, where the meter is the fundamental unit of displacement in the metric system and International System of Units (SI). Pound One pound (1 lb) is the force that produces an acceleration of 32.1740 feet per second squared (32.1740 ft/sec2) when applied against a known standard mass. The acceleration of 32.1740 ft/sec2 is approximately the value of the earth's gravitational acceleration at 45 degrees north latitude. Second One second (1 s or 1 sec) is the time that elapses during 9.192631770 x 10 9 cycles of the radiation produced by the transition between two levels of Cesium 133. It is also 1/86,400 of a m ...
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