Brachistochrone Problem: The Cycloid Solution

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Discussion Overview

The discussion revolves around the Brachistochrone problem, specifically focusing on why the solution to this problem is a cycloid. Participants explore the mathematical derivation and the physical implications of the cycloidal path as the fastest route between two points under the influence of gravity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions why the path of the Brachistochrone is a cycloid and not another function, seeking clarity on the mathematical reasoning behind this conclusion.
  • Another participant suggests that the cycloid makes the best use of gravitational force, allowing for large acceleration initially, which is maintained throughout the path.
  • There is a claim that the equations of motion lead to the cycloid solution, implying that other curves could theoretically have similar characteristics.
  • One participant asserts that the cycloid's path is independent of gravity, stating that a point on a rolling wheel would describe the same cycloid even without gravitational influence.
  • Participants express interest in further exploring the connection between the cycloidal shape and the Brachistochrone problem, indicating a desire for more information on this relationship.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between the cycloid and the Brachistochrone problem, with some asserting mathematical reasoning while others question the physical implications. The discussion remains unresolved regarding the exact nature of this relationship.

Contextual Notes

Participants mention the potential for other curves to exhibit similar properties, indicating that the discussion may depend on specific mathematical definitions and assumptions about the nature of the paths involved.

bomba923
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Brachistochrone derivation

About the brachistochone---

I have calculated the parametric equation for it...but why is this path a cycloid? It does seem fast...but how did they determine that it was a cycloid...not any other function?--Hmm-why exactly does the path of a point of a circle as it rolls down a straight line become the fastest distance between the two points in the brachistrone problem??
 
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Why is it a cycloid? Because it makes 'the best use' of the gravitational force. At first the path is very steep, so the object acquires a large acceleration, and because teher is no friction involved the object keeps this large velocity till the end of the track. Ofcourse there are other paths with the same characteristics, and I think it is a cycloid because this follows from the formulas.

If there is a connection between the shape being the one of a piont on a horizontally moving wheel, and the brachistochrone I would definitely want to hear more...!
 
bomba923 said:
About the brachistochone---

I have calculated the parametric equation for it...but why is this path a cycloid? It does seem fast...but how did they determine that it was a cycloid...not any other function?--

Mathematics and only mathematics.It could have been any other curve similar in shape,but it was the equations that led to the solution.

bomba923 said:
Hmm-why exactly does the path of a point of a circle as it rolls down a straight line become the fastest distance between the two points in the brachistrone problem??

There's no connection between the cycloid followed from a point on rolling wheel and the brahistochrone.The point would describe the same cycliod even in the absence of gravity.

For more detail,check out this wonderful site:you have a model of brahistochrone right on the first page
site
It's in french...But it's math.It's comprehendable.

Daniel.
 
da_willem said:
If there is a connection between the shape being the one of a piont on a horizontally moving wheel, and the brachistochrone I would definitely want to hear more...!

That's was my question in the first place--! Anyways, I'll try to figure it out
 
Please,do tell us if u find it.It would be a really interesting both mathematically and physically result.


Daniel.
 

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