Distance and displacement are defining components of physics. Distance talks to the length and time taken during motion during travelling between two points.
Whereas the displacement explains the shortest distance between two locations of distance that explains the farthest distance between two endpoints of the distance travelled.
Key Takeaways
- Distance is the length of the path traveled by an object.
- Displacement is the distance between the initial and final positions of an object.
- Distance is a scalar quantity, while displacement is a vector quantity considering direction.
Distance vs Displacement
The difference between distance and displacement is that the direction of the distance is not that important vis a vis for displacement. The direction of the distance is fundamental to be considered for calculating displacement.
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Another point to understand about the key difference between distance and displacement is that the path interdependence of distance changes as per the path taken for distance, and the path dependence is not essential to calculate displacement.
Only the initial and final position of the particular part, body or source is important to consider displacement.
Comparison Table
Parameters of Comparison | Distance | Displacement |
---|---|---|
Meaning | Calculation of the space two actual points | Calculation of space two minimum points |
Formula | speed and time | velocity and time |
Quantity (link) | Scalar | Vector |
Time | Never decreases | Decreases with time |
Route | Complete information | No complete information |
Value | Positive | Positive, negative and zero |
Direction | Not considered | Considered |
Indication | Not indicated using an arrow | Indicated using an arrow |
Path | Can be measured on a non-straight path | It cannot be measured on a not straight path. |
What is Distance?
Distance calculates movements. Distance is measured in millimetres, centimetres, meters, and kilometres. Distance explains the total movements of a person, object or thing on speed and time parameters.
Distance measures how much of the area is being travelled while an object is in motion, considering only the magnitude through scalar measurement.
In short, distance gives in the value of the quantity of space between two points in their actual path in a given time frame only. It can be said that distance shares the space between the start and endpoint of a path.
What is Displacement?
Unlike distance, which calculates movements, displacement defines the change of position of objects, persons or a thing.
The change in the position of an object or something in a specific direction between two linear points is called displacement. Displacement is measured by centimetre, meter, and kilometre.
Displacement uses vector measurement in the direction through understanding the magnitude. Considering the oscillations at a few encounters, displacement usually follows the equilibrium on a straight line.
Example: A car travels from the west to the south direction for 5 km, and they take an eastward direction for 10 km; the distance travelled is 15 km. This is the distance. Now, displacement is the point between the east, north and west points which were not travelled. The points or distance between the east and west are joined to calculate the displacement.
Main Differences Between Distance and Displacement
Meaning and Quantity
The distance can be said to be a complete path travelled by someone or a thing, while displacement is the motion of that particular person or object in the selected points only. The selected points have a starting and a final point which is well defined.
Distance is a scalar quantity, while displacement has a vector quantity. As per scalar quantity, the distance doesn’t rely on the direction of motion of an object. A vector quantity is an opposite. Vector quantity depends on the motion of the object.
Indication
Distance is measured in a line and hence has two endpoints. Distance is indicated with two side endpoints shown with an endpoint or a complete stop. Displacement is shown through two arrows at the side of the part of the distance that is to be considered.
Distance:
.________.
And
Displacement < ————- >
Time and Route
When one is travelling, the distance is measured in kilometres. As we move further, the distance increases as time passes.
Displacement only refers to a part of the distance covered, calculated or travelled. Hence, it is correct to say that distance increases with time and displacement reduces with time.
The route of a line of journey or a plan is fixed or defined when measuring a distance. The displacement calculation is rested on the distance travelled.
Hence the route is predefined for distance calculation, which is not the case with displacement.
Path
Distance calculation rests heavily on the path taken. The path to tread may be chosen and predicted, but it is prone to alter and change. Hence, distance changes as her path are taken.
Displacement considers only the initial and final points selected from the entire path that distance calculates.
Formula
Distance = Speed x Time
Displacement- Velocity x Time
Value and Direction
The value of the distance is understood as always greater than or equal to the value of the displacement. Hence, the value of displacement by default is lesser than that of a distance calculation.
Similarly, the direction is not considered calculation for the calculation of distance, and only the unit of measurement is used as a tool to measure distance.
While for the displacement calculation, the direction is essential to consider as the director explains the velocity and time.
- https://www.osapublishing.org/abstract.cfm?uri=aop-4-4-441
- https://www.onepetro.org/journal-paper/PETSOC-04-02-02
Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.