• call
  • chat
  • call
Header Add 1

Header Add 1

Rev. Notes > AS > Physical quantities and units
Previous Topic Physical quantities and units Next Topic



Areas of Physics

Interdisciplanary areas of physics

Quantities in Physics

Base Units

Convention for indicating units

Derived Units

S.I. Units (International System of Units)

Supplementary units

Homogeneity of equations

Significant figures

Rules of Significant figures

Further discussion on Significant figures


Scientific notation

The Avogadro's Constant

Scalars and Vectors

Addition and subtraction of co-planar vectors

Rectangular components of a vector



At the present time, there are three main frontiers of fundamental science.

First, the world of the extremely large, the universe itself,

Radio telescopes now gather information from the far side of the universe and have recently detected, as radio waves, the “firelight” of the big bang which probably started off the expanding universe nearly 20 billion years ago. Second the world of the extremely small, that of the particles such as, electrons, protons, neutrons, mesons and others. The third frontier is the world of complex matter. It is also the world of “middle-sized” things, from molecules at one extreme to the Earth at the other. This is all fundamental physics, which is the heart of science.
But what is physics? According to one definition, physics deals with the study of matter and energy and the relationship between them. The study of physics involves investigating such things as the laws of motion, the structure of space and time, the nature and type of forces that hold different materials together, the interaction between different particles, the interaction of electromagnetic radiation with matter and so on.

Areas of physics

Interdisciplinary areas of physics

 By the end of 19th century many physicists started believing that every thing about physics started believing that every thing about physics has been discovered. However, about the beginning of the twentieth century many new experimental facts revealed that the laws formulated by the previous investigators need modifications. Further researches gave birth to many new disciplines in physics such as nuclear physics which deals with atomic nuclei, particle physics which is concerned with the ultimate particles of which is concerned with the ultimate particles of which the matter is composed, relativistic mechanics which deals with velocities approaching that of light and solid state physics which is concerned with the structure and properties of solids, but this list is by no means exhaustive.
Physics is most fundamental of all sciences and provides other branches of science, basic principles and fundamental laws. This overlapping of physical chemistry, biophysics, astrophysics, and health physics etc. Physics also plays an important role in the development of technology and engineering.
Science and technology are a potent force for change in the outlook of mankind. The information media and fast means of communications have brought all parts of the world in close contact with one another. Events in one part of the world immediately reverberate round the globe.

We are living in the age of information technology. The computer networks are products of chips developed from the basic ideas of physics. The chips are made of silicon. Silicon can be obtained from sand. It is upto us whether w make a sandcastle or a computer out of it.


Add Comment | FAQs | Report Error | | | Share on Twitter
View Comments on this Chapter - Total Comments (4)
Student Said :

Super i got so much of information through

  11/07/15 09:09 AM
Kennyworthy Mphande Said :
nicely explained.
  26/01/15 07:00 PM
benard wilson Said :
very good notes and easy to understand. i wish u can make more of dem
  10/09/14 09:57 PM
muhammad fawad Said :
nice writting..
  06/05/14 06:47 PM


footer 1

Footer Add 1

    Footer Add 2

Signup for our Newsletter

About us:

A team of committed professionals providing free online resources of physics for the learners of IGCSE/AS/ A Level .....