CHAPTER - 01 (UNITS & DIMENSIONS)
Can you live without light.....Think It.......🤔🤔
(PHYSICS AND PHYSICAL QUANTITIES)
Physcs:
Physics is the branch of science, which deals with the study of nature and natural phenomena. The subject matter of physics includes heat, light, sound, electricity, magnetism and the structure of atoms.
For designing a law of physics, a scientific method is followed which includes the verifications with experiments. The physics, attempts are made to measure the quantities with the best accuracy. Thus, physics can also be defined as science of measurement.
Physical Quantities:
All quantities that can be measured are called physical quantities. For example: Distance, Speed, Mass, Force etc.
Types of Physical Quantity:
- Fundamental Quantity: The quantity which is independent of other physical quantities. In mechanics, mass, length and time are called fundamental quantities.
- Derived Quantity: The quantity which is derived from the fundamental quantities is a derived quantity. For example area, speed etc.
UNITS: FUNDAMENTAL AND DERIVED UNITS
Measurement:
In our daily life, we need to express and compare the magnitude of different quantities; this can be done only by measuring them.
Measurement is the comparison of an unknown physical quantity with a known fixed physical quantity.
Unit:
The known fixed physical quantity is called unit.
or
The quantity used as standard for measurement is called unit.
Example-1
when we say that length of the class room is 8 metre, we compare the length of class room with standard quantity of length called metre.
Length of class room = 8 metre
Q = nu
Physical Quantity = Numerical value × unit
Q = Physical Quantity
n = Numerical value
u = Standard unit
Example-2
