Here three paths are shown to reach from A to B. The length of the paths are different in all the above cases.
We call the total length of the path as "Distance".
The path shown in the third image is the shortest. This shortest distance between two points A and B called displacement. But we need to tell its direction also. For instance, its direction is towards right with respect to point A.
"Displacement" is the shortest distance between two points.
This shortest distance must be specified with respect to some reference point (direction). It has both magnitude (a number) as well as direction.
Let's find out the displacement and distance covered by Lily during her journey.
She starts walking from point A and reaches at point B 100 meter rightwards from A. She turns around and finally comes to point C leftwards with respect to A.
As she goes 100 meters rightwards (from point A to B) and comes 50 meters back to point C leftwards (from point to B to C).
Total path she covered = (100 + 50) meters
= 150 meters
So, the distance covered by Lily is 150 meters.
However, her final position (point C) is 50 meter rightwards from the initial position (point A).
So, the displacement = Final position - Intial position
= 50 - 0
= 50 meters rightwards
So, the displacement experienced by Lily is 50 meters rightwards.
Sign Convention
The motion in the right direction from the initial point is considered to be a positive direction.
The motion in the left direction from the initial point is considered to be a negative direction.
Displacement has both magnitude and direction (+/- or rightwards/ leftwards etc). Distance has only magnitude.
[Contributed by administrator on 10. Januar 2018 21:47:10]
Distance versus Displacement
Here three paths are shown to reach from A to B. The length of the paths are different in all the above cases.
We call the total length of the path as "Distance".
The path shown in the third image is the shortest. This shortest distance between two points A and B called displacement. But we need to tell its direction also. For instance, its direction is towards right with respect to point A.
"Displacement" is the shortest distance between two points.
This shortest distance must be specified with respect to some reference point (direction). It has both magnitude (a number) as well as direction.
Let's find out the displacement and distance covered by Lily during her journey.
She starts walking from point A and reaches at point B 100 meter rightwards from A. She turns around and finally comes to point C leftwards with respect to A.
As she goes 100 meters rightwards (from point A to B) and comes 50 meters back to point C leftwards (from point to B to C).
Total path she covered = (100 + 50) meters
= 150 meters
So, the distance covered by Lily is 150 meters.
However, her final position (point C) is 50 meter rightwards from the initial position (point A).
So, the displacement = Final position - Intial position
= 50 - 0
= 50 meters rightwards
So, the displacement experienced by Lily is 50 meters rightwards.
Sign Convention
The motion in the right direction from the initial point is considered to be a positive direction.
The motion in the left direction from the initial point is considered to be a negative direction.
Displacement has both magnitude and direction (+/- or rightwards/ leftwards etc). Distance has only magnitude.