Physics -Important Basics
Scalars and Vectors
Scalar quantities are those quantities which require only the magnitude for their complete specifications.
Some physical quantities which are scalar are mass, length, time, energy, volume, density, temperature, electric charge, electric potential etc.
Vector quantities are those quantities which require magnitude as well as direction for their complete specifications.
Some physical quantities, which are vectors are displacement, velocity, acceleration, force, electric intensity, magnetic intensity, magnetic moment etc.
Unit Vectors –
A unit vector is a vector having a magnitude of unity.
Its only purpose is to describe a direction in space.
Vectors having a common line of action are called collinear vectors.
There are two types of collinear vectors.
One is parallel vector and another is anti parallel vector.
A vector having zero magnitude an arbitrary direction is called zero vector or ‘null vector’and is written as = O vector.
Vectors situated in one plane, irrespective of their directions, are known as co-planar vectors.
Vector whose initial point (tail) is fixed is said to be a localized or a fixed vector.
Non-localized Vectors –
Vector whose initial point (tail) is not fixed is said to be a non-localized or a free vector.