The Difference Between Distance and Displacement for Class 9 Students

As students begin studying physics in class 9, one of the fundamental concepts they learn is the difference between distance and displacement. While these two terms may sound similar, they actually have distinct meanings in the world of physics.

Understanding Distance

Distance is the total length of the path taken during a journey. It is a scalar quantity, which means it has magnitude but no direction. A common tool to measure distance is a meter stick, which measures the length between two points in a straight line. When calculating distance, the path taken does not matter, only the total length.

For example, if a person walks along a curved path from point A to point B, the distance they have covered is the total length of the path between the two points, regardless of the direction or shape of the path.

Understanding Displacement

Displacement, on the other hand, is the distance between the initial position and the final position of an object. It is a vector quantity, which means it has both magnitude and direction. This means it is not just the total length of the journey but a measure of how far an object has moved from its original position.

To calculate displacement, we need to know the initial position and the final position of an object. It’s important to understand that displacement can be zero if the object returns to its initial position. This means that an object can travel a distance but have zero displacement.

For example, if a person walks from point A to point B and then returns to point A, their displacement is zero, even though their distance traveled is not.

Conclusion

In conclusion, distance is a measure of the total length traveled by an object, while displacement is a measure of how far an object has moved from its initial position. While they may seem similar, they have distinct meanings in physics and it is important for class 9 students to understand the difference between the two concepts. As students continue to study physics, they will come to recognize that understanding these concepts is fundamental to the study of motion and force.

Table difference between distance and displacement for class 9

Table Showing the Difference Between Distance and Displacement

	Distance	Displacement
Definition	The total length of the path covered by an object. It is a scalar quantity.	The shortest distance between the initial and final positions of an object, taking into account the object’s direction. It is a vector quantity.
Units of Measurement	Meters (m), kilometers (km), centimeters (cm), etc.	Meters (m), kilometers (km), centimeters (cm), etc. with a direction specified (i.e. North, South, East, West).
Formula	d = Δx + Δy + Δz + …	Δx = xf – xi
Example	A person walks 10 meters east, then 5 meters north, then 3 meters west. The total distance covered is 18 meters.	A person walks 10 meters east, then 5 meters north, then 3 meters west. The displacement is 8.6 meters at an angle of 44.2° north of east.