# Velocity

Velocity of an object is defined as displacement divided by the time taken for displacement.

$$\text{Velocity} = \frac {\text{Displacement}} {\text{Time Taken}}$$
1. Uniform Velocity
An object is said to be moving with a uniform velocity (constant velocity) if it undergoes equal displacements in equal intervals of time, however small these time intervals may be. Uniform velocity means that magnitude as well as direction of velocity remains constant.
2. Variable Velocity
A body is said to be moving with a variable velocity (non-uniform velocity) if there is a change in its magnitude or direction or both.
A body moving with a constant speed in a circle has a variable velocity. Although speed is constant, the direction of velocity of body is changing from instant to instant.
3. Average Velocity
When an object moves with variable velocity, we describe its motion in terms of average velocity.

The average velocity of an object is defined as displacement divided by time taken for displacement. It’s denoted by a bar over v.
4. Instantaneous Velocity
The velocity of an object at any given instant of time is called its instantaneous velocity.
Consider an object moving with a uniform velocity of 5 ms-1 in a straight line. It means that object is moving with a speed of 5 ms-1 in a straight line. The velocity of the object at any instant would be 5 ms-1. Therefore, instantaneous velocity of this object is 5 ms-1.