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Distance and Displacement

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Last updated date: 19th Mar 2024
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Definition of Distance and Displacement

The concept of distance is plain, it is just the measure of “how much on a ground an object has covered” during its motion.


However, displacement has the same principle as distance, the difference lies in its concept, which states that displacement tells us “how far out of place an object has covered a distance.”


So, did you notice any difference in the statements of distance and displacement, when both the terms give a measure of “how much object covered?


Also, if they have the same meaning, then why do we study them separately and what role these terms have in Newtonian mechanics?


Answers to all these questions will be provided in a plain manner along with illustrating examples on this page.


Now, let us understand the “Concept of Distance and Displacement”:


How Do We Differentiate a Distance from Displacement?

From the above text, we got a basic understanding of the two terms that we will discuss on this page.

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Scenario 1: Now, let us assume that a lady called “Dipa” (distance) is travelling from city A to city B to attend her cousin’s marriage. Without looking at the Google Map, she believes that whichever path she goes to, she will definitely reach her cousin’s marriage. So, here, Dipa is a distance who, irrespective of the direction, takes on her journey.  

Hence, we conclude that Distance is independent of the direction, it implies that the magnitude of the path travelled is taken into account. Thus, Distance is a scalar quantity.


The distance of an object can be defined as the complete path travelled by an object. For example. if a car travels east for 5 km and takes a turn to travel north for another 8 km, the total distance travelled by car shall be 13 km. The distance can never be zero or negative and it is always more than the displacement of the object. The distance of the object gives complete information about the path travelled by the object.


Scenario 2: Now, let us assume that Dipa’s cousin Disha calls Dipa to ask the time she will reach the marriage hall, as the marriage occasions are soon going to start. Dipa says I’m around 50 km away  (which is obviously a distance) and it may hardly take 1 hr to reach there.


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Disha asks her the path she is taking to reach the destination, Dipa replies by saying that she is taking the “ABC” path. 


Disha suggests her sister take the “XYZ” path to reach the spot within 15 minutes, and Dipa follows the same and reaches the destination in just 10 minutes.


So, did you notice a difference in scenarios 1 and 2? Was there something more/less in scenario 2? Yes, it was. Now, let us understand how.


When we notice  in scenario 2, we got a factor called “ABC” that was replaced by “XYZ”.

Here, ABC was just a distance Dipa was taking irrespective of the path travelled and when she gets a suggestion from her sister to take on path “XYZ.” This XYZ was the shortest path that led Dipa to reach the destination before an hour. 


Another factor was distance and time, which was replaced from ABC to XYZ (assume from 50 km to 15 km) and 1 hr to 10 minutes, respectively.


So, this is how displacement is an advantage over distance, as it is the shortest path taken by an object during its motion. As we notice that direction factor is also there, so obviously, displacement is a vector quantity that considers both the magnitude and direction of the path taken. Therefore, we understand that the displacement of an object can be defined as the overall motion of the object or the minimum distance between the starting point of the object and the final position of the object. 


For Example: if we consider the same example as given earlier, the total displacement of the object will be the length of the line joining the two positions. The displacement of an object is usually shorter or equal to the distance travelled by the object. The displacement of the object does not give the proper information about the path travelled by the object.