Skip to main content

Distance and Displacement | How are they different?

Distance and displacement are two quantities, one is scalar(distance), and one is vector(displacement) but they still seem to mean the same thing. 

Let us understand what these concepts mean, and how they are different.


What is Distance?
Distance is a scalar quantity that refers to the length of the path which an object has covered during its motion.

A__________B________C

Let A, B, and C be three points which form a straight line. An object starts at point A and travels through B and reaches C, and then it moves back along the same path to get back to A through B.

In this case the distance travelled by the object is twice the length from A to C.

In order to describe distance, we only need to specify the numerical value and not the direction of motion. This numerical value is called as the magnitude. This is the reason why distance is a scalar quantity.


What is Displacement?
Displacement is a vector quantity that refers to the shortest distance measured from the initial to the final position of an object.

A__________B________C

Let's take the exact same scenario where  A, B, and C are three points which form a straight line. An object starts at point A and travels through B and reaches C, and then it moves back along the same path to get back to A through B.

There will actually be no displacement here. This is because the object has come back to where it originally started. The initial and final positions are the same.

To describe displacement, we need to consider the magnitude as well as the direction of Motion. This is why displacement is a vector quantity.

When you travel on road, for example, you make a lot of turns and your direction of motion keeps changing. 

When you reach your final position, even though you may feel like you have travelled for a long time(and you have travelled a large distance), the shortest distance in a straight line from your initial position to your final position, that is the displacement, can actually be much shorter than the actual distance, that is the length of the path you have covered.


Can the distance be equal to the displacement?
Yes, of course the distance and displacement can be equal.

If an object travels in a straight line without changing its direction, then it will already be travelling the shortest distance to reach from the initial position to the final position. This means that the distance and displacement will be the same.



In physics, distance and displacement are used to describe the overall motion of an object and to determine its final position with respect to it's initial position at a given time.


There are devices which measure the distance travelled. Such a device is called as an odometer. You can find such devices in automobiles.

I think you should be able to understand the concepts of distance and displacement well now. I hope you learned something new today by reading this blog post.

Thank you for reading!

- Arya Bharaty




 

Comments

Popular posts from this blog

THE MYSTERIOUS OCTAHEDRON

Today's post is more related to mathematics, as you can tell from the title. I'll be telling you about the amazing solid shape, the octahedron. WHAT YOU WILL LEARN TODAY : We will have found-  -->The derivation of the formula for the volume of the octahedron. -->The ratio of the volume of an octahedron when placed inside a cube with its vertices touching the centers of the faces of the cube and the volume of the cube.  So! Let's begin! You will have to understand platonic solids first. PLATONIC SOLIDS: Platonic solids are five geometric solids that have congruent and regular sides that meet at three-dimensional angles.  Plato used them to explain the structure of the universe. Hence, the name 'Platonic'. There are five Platonic solids:  the tetrahedron with four faces,  the cube with six faces,  the octahedron with eight faces,  the dodecahedron with twelve faces,  and the icosahedron with twenty faces.   They are used in many fields, including biomedical rese...

Refraction of Light

You must have heard of reflection of light. It's when a ray of light bounces back from a surface.  When a light ray hits a mirror, it bounces back with the same angle as the angle with which it hit the mirror. The angle of incidence is always equal to the angle of reflection But what if instead of a mirror, there is a transparent surface? In such cases, the light ray goes through the surface, and undergoes refraction.  What is refraction? Refraction is the bending of light when it goes from one medium to another. This happens because the speed of light changes across two different media. When a ray of light is perpendicular to the normal, it travels to the other medium without bending. The ray of light only bends when it goes obliquely from one medium to another. This bending of light depends on the medium through which light is travelling. Optical Density • Rarer medium:  The medium through which the speed of light is more is an optically rarer medium. • Denser medium: The medium...

General Relativity Explained

Have you ever heard about General relativity?  General relativity is a remarkable theory published by the well known physicist Albert Einstein. Let us know more about general relativity. General relativity is the geometric theory of gravitation published by Albert Einstein. Albert Einstein published this theory in 1915. It is the current description of gravitation in modern physics. General relativity generalizes special relativity and Newton's law of universal gravitation , and gives a unified description of gravity as a geometric property of space and time, or space-time . THE CURVATURE OF SPACE-TIME AND THE EINSTEIN FIELD EQUATIONS The  curvature of space-time is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations. That is a system of partial differential equations. The Einstein field equations comprise a set of 10 equations in Albert Einstein's general theory of ...