Scalar and vector quantities

Scalar quantities: Those physical quantities which have magnitude but no direction are called scalar quantities. e.g. Area, volume, mass, speed, density, distance, charge, energy, temperature, length, time, etc.

* Scalar quantities can be added, subtracted or multiplied by using simple rules of algebra.

* Scalar quantities change if their magnitude is changed. 

* Scalar quantities are represented by ordinary letters.

Vector quantities: Those physical quantities which have magnitude as well as direction are called vector quantities. e.g. Displacement, velocity, acceleration, momentum, force, impulse, electric field, gravitational field etc.

* Vectors do not follow the laws of algebra, i.e., vectors can not be added, subtracted or multiplied by the way of scalars. Vectors can be added, subtracted or multiplied by using rules of vector algebra. The division of a vector by another vector is not a valid operation in vector algebra.

* Vector quantities change if either their magnitude or direction or both are changed. 

* Vector quantities are represented by letters having arrow over them.