Does the coefficient of restitution depend on the collision "type"?

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Discussion Overview

The discussion revolves around whether the coefficient of restitution is influenced by the type of collision, specifically comparing elastic collisions on a frictionless surface to inelastic collisions involving a drop from height. Participants explore the implications of different collision scenarios on the coefficient of restitution.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants question if the coefficient of restitution remains constant across different types of collisions, such as a direct collision versus a drop collision.
  • One participant suggests that the coefficient may be approximately constant within a limited range of collision velocities but may not apply universally across all collision types.
  • Concerns are raised about potential outcomes like cracking or permanent deformation in collisions, which may affect the coefficient of restitution.
  • There is a suggestion to look for experimental articles that investigate the coefficient of restitution in various collision scenarios.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the applicability of a single coefficient of restitution across different collision types, indicating that multiple competing views remain without a clear consensus.

Contextual Notes

Participants note that assumptions about the integrity of the objects involved in collisions (e.g., whether they break or deform) can significantly influence the discussion about the coefficient of restitution.

erfz
Probably a very simple question:

Does the coefficient of restitution depend on the collision being performed?

Consider two masses ##m_1## and ##m_2##. They are placed on a frictionless horizontal table and ##m_1## is given an initial velocity, collides 1-dimensionally with ##m_2##, and the coefficient of restitution is calculated from the initial and final velocities.

If instead I had ##m_2## on a table and ##m_1## was dropped from a height ##h_i## onto ##m_2##, and then came up to a height ##h_f##, would the calculated coefficient of restitution be the same here as in the first situation?
 
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erfz said:
Probably a very simple question:

Does the coefficient of restitution depend on the collision being performed?

Consider two masses ##m_1## and ##m_2##. They are placed on a frictionless horizontal table and ##m_1## is given an initial velocity, collides 1-dimensionally with ##m_2##, and the coefficient of restitution is calculated from the initial and final velocities.

If instead I had ##m_2## on a table and ##m_1## was dropped from a height ##h_i## onto ##m_2##, and then came up to a height ##h_f##, would the calculated coefficient of restitution be the same here as in the first situation?

If you dropped one mass from high enough, then possibly the objects would break apart, rather than bounce off each other.

This suggests to me that the coefficient of restitution for two objects would tend to be approximately constant across a limited range of collision velocities, but in general a single coefficient would not apply across all possible collisions.
 
PeroK said:
If you dropped one mass from high enough, then possibly the objects would break apart, rather than bounce off each other.

This suggests to me that the coefficient of restitution for two objects would tend to be approximately constant across a limited range of collision velocities, but in general a single coefficient would not apply across all possible collisions.
But assuming that they do not break, the coefficient can be applied to both scenarios?
 
erfz said:
But assuming that they do not break, the coefficient can be applied to both scenarios?
In general you may get cracks or permanent deformations, which I suspect will be non-linear in nature.

Have you tried looking online for articles on experiments looking at this?
 
PeroK said:
In general you may get cracks or permanent deformations, which I suspect will be non-linear in nature.

Have you tried looking online for articles on experiments looking at this?
No, but that is a good idea.
Thank you!
 

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