# Difference between speed and velocity class 9

Though we use the terms speed and velocity interchangeably without knowing the actual concept, but there is a difference between speed and velocity which everyone must know.

In fact, it is also an examiner favorite topic, asked in board exams and competitive entrance exams like JEE and NEET and competitive exams like RRB NTPC, RRB Group D, SSC CGL and state PSC’s.

Both speed and velocity convey different meanings, that is speed refers to the time rate at which an object moves along a path, whereas the rate and direction of that object’s movement will be velocity.

Here we provide the difference between speed and velocity based on NCERT in tabular form.

## Difference between speed and velocity class 9 NCERT

Properties Speed Velocity
Definition The rate at which an object covers a certain distance is known as speed. The rate at which an object changes position in a certain direction is known as velocity.

Or ,

Velocity is the speed of an object moving in a definite direction

Formula Speed = Distance / Time Velocity = Displacement / Time
Type of quantity Speed is a Scalar quantity Velocity is a Vector quantity
Magnitude Speed of a body is Positive or Zero but it cannot be negative. The Velocity of a body can be zero, negative, or positive.
Change of direction The average speed will continue to count even if the object changes direction. The velocity of the object changes with the change in direction, therefore the object must follow one direction.
Interrelation Speed may or may not be equal to the velocity. An object may possess different velocities but the same speed.
Average Value The average speed of an object is the total distance travelled by the object divided by the total time taken. The Average velocity is given by the arithmetic mean of initial velocity and final velocity for a given period of time.
Formula of
Average value
Average Speed (s) = Total distance travelled (d) / Total time taken (t) Average Velocity (v) = [Initial velocity (u)+ Final velocity (v)] / 2
Example Suppose, a motor van travelling at 20 m/s , The speed of the motor van is  30 m/s. Suppose a Bus going towards the north direction with an average speed of 30 km/h, So the velocity of the Bus is 30 Kilometers per hour northwards.

Note:

♦ Always remember Speed and velocity have the same SI units, that is, m s –1 or m/s.  (Meter per second)  