Why is the distance always greater than or equal to the displacement?

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Homework Help Overview

The discussion revolves around the relationship between distance and displacement in physics, particularly why distance is always greater than or equal to displacement. Participants are exploring the definitions and implications of these concepts.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are discussing examples, such as traveling around a circle, to illustrate the difference between distance and displacement. There are questions about the underlying reasons for the inequality and the mathematical principles involved, including references to vector properties and the triangle inequality.

Discussion Status

The discussion is active, with participants providing examples and attempting to clarify the concepts. Some have offered mathematical insights, while others are still questioning the foundational reasoning behind the relationship between distance and displacement.

Contextual Notes

There is a focus on the definitions of distance as a scalar quantity and displacement as a vector, with some participants emphasizing the need for a scientific explanation of the inequality. The conversation reflects a mix of intuitive reasoning and mathematical exploration.

jacyh
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Why is the distance never less than the displacement?
I can't seem to find a scientific explanation for it. :confused:
 
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think about traveling half way around a circle, the distance traveled would be half the circumference, and the displacement would be the diameter.

in this case distance > displacement

distance can be equal to the displacement (if you travel in a straight line), but it can never be less.
 
distance can be equal to the displacement (if you travel in a straight line), but it can never be less.

I know, but... why? Haha.
 
just think about the example i gave you and think of any other ones you can think of... the displacement will never be greater than the distance.

Think of distance as "distance travelled"

So if you're going from point A to point B in any situation you can think of (around curves, over mountains etc...) The distance traveled will be greater because you had travel "around" things.
The displacement is a straight line between point A and B, so it is always the shortest possible distance.
 
Last edited:
Strictly speaking, distance is a magnitude but displacement is a vector.
So, yoiu really mean
"why is distance >= magnitude of displacement ?"

Mathematically,
\int \left| d\vec s \right| \geq \left| \int d\vec s \right|

Essentially, distance [ the arc-length of a curve from A to B ] is the sum of non-negative quantities.
The magntude of displacement [ the magnitude of a vector from A to B ] is the non-negative magnitude of a sum-of-(signed)-vector-quantities.
The proof of the inequality is essentially the triangle inequality.
 
distance is total distance traveled, displacement is from the initial location to the final location.
 
The displacement is the shortest way possible from the start to the finish (that is, it's a line); thus, nothing can be shorter.
 

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