Physics chapter 1 notes

Class 11
Chapter-1
Introduction To Physics
Short Notes for 2021-22

Physics is the branch to study about Nature and Natural Phenomenon.

Physics is derived from a greek word Phusis which means nature.The word Bhotiki in Sanskrit also mean same i.e Nature.

Definetion of Physics-

Physics is a branch of science in which we study about the general properties of states of matter, forms of energy and there mutual transformations, force of interaction between particles of matter.

Matter-

Substances that occupy space and have mass and can be feel by our senses(hear,sight,taste,smell), such substances are called matter.ex- air, water, stone etc.

Energy-

Energy neither neither has mass nor occupy space, and only can be feel by our senses.

It is present in each and every substance in universe.
Existence of energy is in many form like Mechanical, Thermal, Nuclear etc.
Energy is the capacity to do work.
Therefore, can be measured by the work which it can do.

According to Einstein

Matter and Energy are interconvertible( i.e matter can be converted to energy and energy can be converted into matter.)

E=mc2

Where C = Speed of light in vaccum(3.8 x 10⁸ m/s)
This equation is also called as Einstein's mass-energy relation.

There are Seven Branches of Physics which are as follows-:

Mechanics and General Properties

Heat And Thermodynamics

Light

Sound

Magnetism

Electricity And Electrodynamics

Modern Physics

Modern Physics has also seven branches which are as follows-:

Atomic and Nuclear Physics
Quantum Physics
Particle Physics
Electrolysis
Solid-State Physics
Condensed Matter Physics
Nano Physics

Nowdays, Physics is studied as classical and Modern. In classical physics we study all the branches of Physics except Modern Physics(i.e Atomic and Nuclear Physics,Quantum Physics,Particle Physics,Electrolysis,Solid-State Physics,Condensed Matter Physics,Nano Physics). And in Modern Physics we study the branches of only modern Physics.