Physical quantities are classified into two categories on the basis of magnitude and direction. One is scalar and other is vector. Here in this article, we will discuss about scalar and vectors.
Scalar quantities:
The physical quantities which have only magnitude, and no direction are called scalar quantities or scalars. A scalar quantity can be specified by a single number, along with the proper unit.
Examples:
Mass, volume, density, time, temperature, electric current, etc.
Vector quantities:
The physical quantities which have both magnitude and direction and obey the laws of vector addition are called vector quantities or vectors. A vector quantity is specified by a number with a unit and its direction.
Examples:
Displacement, velocity, force, momentum, etc.
Difference between scalars and vectors:
| Scalars | Vectors |
| 1. Scalars have only magnitude. | Vectors have both magnitude and direction. |
| 2. They change if their magnitude changes. | They change if either their magnitude, direction or both change. |
| 3. They can be added according to ordinary laws of algebra. | They can be added only by using special laws of vector addition. |