Vectors and Scalars:

Those physical quantities which have only magnitude but no direction are called scalars. For eg. Mass, Speed, Distance, Work, Energy, Charge, Current etc.

Those physical quantities which have both magnitude and direction are called vectors. For eg. Displacement, Force, Velocity, Acceleration, Linear Momentum etc.

Vectors are generally represented by a letter with arrow head.

Types of Vectors:

i]   Unit Vector

     A vector is said to be a unit vector if its magnitude is one.

     

ii]  Null Vector

     If the magnitude of a vector is zero, the vector is said to be the null vector.

       

iii]  Negative Vector

   Two vectors are said to be negative to each other if they have same magnitude but opposite in direction.  

iv] Coplaner Vector:

     Two vectors are said to be coplaner if they lies on a same plane.