A vector has direction and magnitude both but scalar has only magnitude . Magnitude of a vector a is denoted by | a | or a . It is non-negative scalar .
Equality of Vectors
Two vectors a and b are said to be equal written as a = b , if they have ( i ) same length ( ii ) the same or parallel support and ( iii ) the same sense .
Types of Vectors
( i ) Zero or Null Vector A vector whose initial and terminal points are coincident is called zero or null vector . It is denoted by 0 .
( ii ) Unit Vector A vector whose magnitude is unity is called a unit vector which is denoted by nˆ
( iii ) Free Vectors If the initial point of a vector is not specified , then it is said to be a free vector .
( iv ) Negative of a Vector A vector having the same magnitude as that of a given vector a and the direction opposite to that of a is called the negative of a and it is denoted by — a .
( v ) Like and Unlike Vectors Vectors are said to be like when they have the same direction and unlike when they have opposite direction .
( vi ) Collinear or Parallel Vectors Vectors having the same or parallel supports are called collinear vectors .
( vii ) Coinitial Vectors Vectors having same initial point are called coinitial vectors .
( viii ) Coterminous Vectors Vectors having the same terminal point are called coterminous vectors .
( ix ) Localized Vectors A vector which is drawn parallel to a given vector through a specified point in space is called localized vector .