What Part of a Ball Hitting a Parabola Hits the Focal Point?

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    Ball Parabola
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Discussion Overview

The discussion revolves around the dynamics of a 1" ball impacting the inside of a parabola and its relationship to the focal point. Participants explore the conditions under which different parts of the ball (center or edge) may contact the focal point, considering various angles of incidence and the geometry involved.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether the edge or the center of the ball strikes the focal point when the ball hits the parabola.
  • Another participant suggests that the outer edge of the ball would be the part that hits the focal point.
  • A participant who modeled the scenario using geometry software notes that there is no definitive answer, as the outcome depends on the ball's trajectory relative to the parabola's axis.
  • This participant also indicates that if the ball follows the parabola's axis, it will hit the focal point directly, but in other cases, it may miss the focus entirely or hit it with its side under certain conditions.
  • Another participant expresses confusion about the conditions under which the ball might miss the focus completely, seeking clarification on the diagram provided.
  • A later reply emphasizes that for a ball flying parallel to the axis, only center-to-side impacts are possible, but this may not hold true for other angles of incidence.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the center or edge of the ball contacts the focal point, and multiple competing views regarding the conditions of impact remain unresolved.

Contextual Notes

The discussion highlights the dependence on the angle of incidence and the specific trajectory of the ball, which are not fully defined in the problem statement.

Photon713
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1" ball hitting Parabola

If a 1" ball hits the inside of a parabola, what part of the ball hits the focal point?
Is it the edge that strikes the inside of the parabola or the center of the ball?
Thank You
 
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What are your thoughts on the matter?
 


I think it would be the outer edge of the ball.
 


I modeled the problem using rhino geometry. Attached 1 pic with a ball crossing the focus.
There is no exact answer.

If the ball follows the parabola axis it will hit dead center (obvious).
But in all other situations, the ball might cross the focus or even miss it completely.
The ball can hit the focus with it's side given certain conditions.
 

Attachments

  • Paraball.jpg
    Paraball.jpg
    12.3 KB · Views: 515


Lok said:
I modeled the problem using rhino geometry. Attached 1 pic with a ball crossing the focus.
There is no exact answer.

If the ball follows the parabola axis it will hit dead center (obvious).
But in all other situations, the ball might cross the focus or even miss it completely.
The ball can hit the focus with it's side given certain conditions.
Cool. But I don't see from your diagram under what circumstances it would miss the focus completely.
 


Thank You...

I am attaching an image that represents a 1" ball bearing hitting the inside of a parabola.
Which line represents the passage through the focal point, center or edge? Is the result always the same no matter where the bearing hits the side?
 

Attachments

  • Parabola7.7x4.jpg
    Parabola7.7x4.jpg
    8.3 KB · Views: 518


DaveC426913 said:
Cool. But I don't see from your diagram under what circumstances it would miss the focus completely.

For ball flying parallel to the axis there are only center to side solutions. But for different angles it is not true. The problem did not specify parallelism though.
 

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