Page 99 - Science and Measurement
* Science and Measurement *
Science: - The knowledge obtained by careful and systematic experiments and tests is called science.
•There are two branches of science
1. Physical Science
2. Biological Science
1. Physical Science- That branch of science, under which inanimate objects and their related events are studied in detail, is called physical science.
2. Biology Science- That branch of science, under which living things and their related events are studied in detail, is called Biological Science.
•There are two branches of science
1. Physical Science
2. Biological Science
1. Physical Science- That branch of science, under which inanimate objects and their related events are studied in detail, is called physical science.
2. Biology Science- That branch of science, under which living things and their related events are studied in detail, is called Biological Science.
•There are two branches of physics
1. Physics
2. Chemistry
1. Physics- The branch of science in which nature and various natural phenomena occurring in nature are studied is called physics.
1. Physics
2. Chemistry
1. Physics- The branch of science in which nature and various natural phenomena occurring in nature are studied is called physics.
• Unit :- There is only such a standard (Stander) which is used to measure the physical amount.
Example: - foot, centimeter, meter, gram, kilogram, second, newton, joule
• Unit Type
1. Fundamental Unit
2. Derived unit
3. Supplementary units
1.Fundamental unit: - Such a unit which does not depend on any other unit, that is, such a unit from which all other units are obtained, is called a Fundamental unit.
Since the number of Fundamental quantities is 7. Therefore the Fundamental units are 7.
Fundamental quantities → Fundamental units
1. Length → Meter
2. Mass → Kilogram
3. Time → Second
4. Temperature → Kelvin
5. Luminous Intesity → Candela
6. Current → ampere
7. Mass of substances in the field of chemistry → mole
**
2. Derived units:- Such units of physical quantities which are obtained from fundamental units are called Derived units.
**
2. Derived units:- Such units of physical quantities which are obtained from fundamental units are called Derived units.
For example: - Unit of speed = Unit of distance / Unit of time = m / sec
Unit of density = Unit of mass / Unit of volume = kg /m3
3. Supplementary units:- Those units which help the basic units are called Supplementary units.
For example :- units of plane angle and solid angle
# Following are some systems of the world
1.F. P. S. System [Foot Pound Second System] :-
This is the British system. In this system, length is measured in feet, mass in pounds, and time in seconds.
It is also called English method.
2. C.G.S. System [Centimeter Gram Second System] :-
This is the French system. In this system, length is measured in centimetres, mass in grams and time in seconds.
It is also called metric system.
3.M.K.S. System [Meter Kilogram Second System] :-
This is the French system. In this system, length is measured in meters, mass in kilograms and time in seconds.
4. S.I. System [International System] :-
This is also the French system. This system M.K.S. modified form of the system.
Nowadays SI system is prevalent for accurate measurement.
• Vector quantity: - The quantity which requires both magnitude and direction to be fully expressed is called vector quantity.
Eg:- Velocity, Displacement, Acceleration, Hair, Momentum, Weight, Electric field
• Scalar quantity: - The quantity which requires only magnitude to be fully expressed is called scalar quantity.
Such as: - distance, mass, time, volume, energy, density, work, temperature, speed, electric charge, electric current
