## Friday, February 3, 2017

### Units and Dimensions an Introduction Video Lesson

We are dealing with the basics of concepts units and dimensions in a video lesson. Physical quantity is a way of understanding nature and its physics applications and to measure them, we use units.

Introduction to Units

Physical quantities are helpful in understanding the nature in terms of measurement. We try to understand the world around us with minimum physical quantities and they are the alphabets and words of the physics language. If a physical quantity is independent of any other physical quantities, they are called fundamental physical quantities and they are the irreducible set of quantities to represent other things in the nature around. Length, mass and time are basic examples of fundamental physical quantities.

Other physical quantities are derived basing on this fundamental quantities and they are called derived physical quantities. Velocity, acceleration and force are the some of the examples of derived physical quantities. To measure this physical quantities, we need to use units. Unit is a way of measuring the physical quantities in a standard way that is acceptable to all.

As physical quantities are of two types, the units are also two types and they are fundamental and derived units. To measure the fundamental physical quantities, we have fundamental units with different kinds of systems like FPS,CGS,MKS and SI system of units. We can further define and write units for the derived quantities based on the the fundamental system of units. At present we are using SI system as the standard system to measure the fundamental physical quantities.

Introduction to Dimensions

Each physical quantity is either a fundamental or derived physical quantity. Derived physical quantity is obtained from fundamental quantity by manipulating the fundamental quantities as per the requirement of the concepts and applications. The representation of a physical quantity in terms of fundamental quantities is called dimensional formula and the powers to which the fundamental quantities are raised are called dimensions. Thus using the dimensional formula, we will be knowing the content of fundamental quantities in it.

### Oscillations Problems with Solution Three

Writing dimensional formula

Errors and approximations

Units and Dimensions Problems and Solutions One