Loading in 2 Seconds...
Loading in 2 Seconds...
Take Home Tasks! Define measurement. Give and describe the two systems of measurement. What do you mean by SI?. A Glimpse in the History of . MeAsUReMEnT. Weights and measures may be ranked among the necessaries of life to every individual of human society.
Give and describe the two systems of measurement.
What do you mean by SI?
Weights and measures may be ranked among the necessaries of life to every individual of human society.
Early Babylonian and Egyptian records and the Bible indicate that length was first measured with the forearm, hand or finger and the time was measured by the periods of the sun, moon and other heavenly bodies.
The English people also started measuring objects in terms of body distances. They say, for instance,
Through Royal edicts, England by the 18th century had achieved a greater degree of standardization than other European countries.
The English system were well suited to commerce and trade because they had been developed and refined to meet commercial needs.
Through English colonization and its dominance of world during the 17th, 18th and 19th centuries, the English system of measurement units became established in many parts of the world, including the American colonies.
In 1584, the book De Thienda by Simon Stevenius was published, preparing a decimal system of units and money
In 1670, Gabriel Mouton, Vicar of St. Paul of Lyons and an astronomer proposed a comprehensive decimal measurement system based on the length of one minute of arc of a great circle of the Earth.
Then in 1790, the French Academy of Science was commissioned by the National Assembly of France to design a new system of units for throughout the world.
The unit of length was to be the portion of the earth’s circumference.
Furthermore, larger and smaller multiples of each unit were to be created by multiplying or dividing the basic units by 10 and its powers. Similar calculations in the metric system could be performed simply by shifting the decimal point. Thus, the metric system is a “base-10” or “decimal” system.
Metre/meterwas the assigned unit of length.
-derived from the Greek word metron- “measures”.
The initial metric unit of mass, the “gram”, was defined as the mass of one cubic centimeter (a cube that is 0.01 meter on each side) of water at its temperature of maximum density.
The cubic decimeter (a cube 0.1 meter on each side) was chosen as the unit for capacity.
The fluid volume measurement for the cubic decimeter was given the name “liter”.
The principles of the metric system brought order into the conflicting traditional system of weights and measures then being used.
In 1960, the General Conference on Weights and Measures, the diplomatic organization made up of the signatory nations to the Meter Convention, adopted an extensive revision and simplification of the system. Seven units were established as the basic units for the system:
1. Meter for length (m)
2. Kilogram for mass (kg)
3. Second for time (s)
4. Ampere for electric current (A)
5. Kelvin for thermodynamic temperature (K)
6. Mole for the amount of substance (mol)
7. Candela for luminous intensity (cd)
The name Systeme International d’Unites(International System of Units), with international abbreviation SI, was adopted for this modern metric system.
-may be expressed as the interval or distance between two points. In 1983, the meter was defined as the length of path traveled by light in a vacuum.
-the amount of matter in any chosen object.
Kilogram is defined as the mass of substance as compared to that of a standard cylinder of platinum-iridium alloy, which is kept in the International Bureau of Weights and Measures.
-the force exerted by gravity on an object
-the interval between two events at the same place in space.
Amount of substance
-mole is the amount of substance of a system
-any continuous system wherein electrons flow from the point of lowest potential to the point of highest potential
Ampere is the basic unit of electric current. It is named after the French physicist Andre Ampere (1775-1836)
-the average kinetic energy in molecules or atoms of substances. Kelvin is defined as 1/273.16th of the thermodynamic temperature of the triple point of water.
-is an expression of the amount of light power emanating from a point of source. Candela is defined as the intensity of a source of light of a specified frequency, which gives a specified amount of power in a given direction.
-combination of base units produce derived units
-the measurement of the extent of a surface and is measured by multiplying the length by the width.
-the space occupied by a body and is measured by multiplying the length (width) by the height.
-condition of a body that determines the transfer of heat to or from other bodies.
4 main temperature scales:
DGFahrenheit (1686-1736), a German physicist, called the freezing point of water 32 degrees and the boiling point 212 degrees.
Anders Celsius (1701-1744), a Swedish astronomer, proposed the 100-degree scale
-a Scottish Mathematician and physicist, worked with J.P. Joule in about 1862 and produced an absolute scale of temperature.
Their work gave birth to the idea of absolute zero, whose value is -273.15 degrees on the Celsius scale.
-a Scottish engineer and scientist promoted the Kelvin scale in its Fahrenheit form, when the equivalent value of absolute zero is -459.67 degrees Fahrenheit.
-the ratio of mass in grams and volume in cubic centimeter, making the unit of density g/cm3