Speed and Velocity

What is Speed?

Speed of an object can be defined as the distance travelled by an object in given time. It is how fast an object is moving. If the object is not moving then the speed of the object is said to be 0.

Speed = Distance / Time

Speed is scalar quantity which means it does not have direction. The SI unit of speed is meters per second (m/s). In day to day usage common units of speed are kilometre / hour (km/hr) or miles per hour (mph).

What is Velocity?

Velocity of an object is defined as the rate at which that object changes its position. Velocity is a vector quantity as it takes both magnitude and direction in account.

Since,

Speed = Distance / Time

Velocity = Displacement / Time

Here, displacement is the distance travelled in a given direction.

Velocity is a basic concept of kinematics which deals with the motion of bodies. The SI unit of velocity is meter per second (m/s).