What is Velocity?

Velocity = Displacement / Time

• The velocity of a body is defined as the displacement covered by the body per unit time.
• Velocity describes both direction and speed of an object’s motion.
• It is the rate of change in displacement with respect to time.
• Its SI unit is meter per second (ms^-1).
• It is a vector quantity i.e., it has both magnitude and direction.  
• It can be positive, negative or zero.

Types of Velocity

The types of velocity are mentioned below:

• Constant Velocity: The velocity which does not changes its magnitude and direction and travels in a straight line is called constant velocity.
• Changing Velocity: The velocity which changes its magnitude or direction, or both is called as changing velocity or acceleration. 
• Instantaneous Velocity: The velocity of a body at any instant is called as instantaneous velocity.
• Terminal Velocity: The velocity of the body obtained by falling down due to gravity is called the terminal velocity.
• Relative Velocity: The velocity calculated between two objects in a single coordinate system is called relative velocity.

Example of Velocity

Assume a person walks for 2 hours from point A to point B, which is 6 kilometers west. To calculate the velocity, use the formula: Velocity = Displacement / time.

Velocity = 6km (west) / 2 hours = 3 km/h (west)

Therefore, the person’s velocity is 3 km/h west. This value represents both speed and direction of the person.

This article is about the difference between speed and velocity. Speed is the rate of change of distance according to time. It is scalar quantity i.e. speed has magnitude but no direction. Velocity is the rate of change of displacement according to time. It is vector quantity i.e. velocity has both magnitude and direction. Speed is the ratio of distance to time and velocity is the ratio of displacement to time. Speed magnitude is a non-zero positive number while velocity magnitude can be positive, negative, or zero.