What causes an object to eventually come to rest after bouncing indefinitely?

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Discussion Overview

The discussion centers around the mechanics of an object bouncing and the factors that contribute to it eventually coming to rest. It explores the implications of the coefficient of restitution and the idealized assumptions in physics, particularly in the context of bouncing objects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant presents a mathematical model showing that if an object bounces indefinitely, it theoretically never comes to rest, as the velocity after each bounce decreases by a factor of the coefficient of restitution.
  • Another participant clarifies the definition of the coefficient of restitution, emphasizing its application in idealized scenarios and noting that real-world factors may alter the outcomes.
  • There is a discussion about the assumptions made in the model, particularly regarding the object being treated as a point particle and the implications of its size on the bouncing behavior.
  • A participant corrects a notation issue regarding subscripts used to denote the velocities after each bounce.
  • Further clarification is sought on the logic behind the mathematical reasoning presented, indicating a desire for precision in the discussion.

Areas of Agreement / Disagreement

Participants express differing views on the application of the coefficient of restitution and the assumptions made in the bouncing model. The discussion remains unresolved, with multiple competing perspectives on the physical reality versus idealized models.

Contextual Notes

The discussion highlights limitations in the assumptions made, such as the treatment of the object as a point particle and the neglect of real-world phenomena that could affect the bouncing behavior.

Shoku Z
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Suppose that an object is dropped from a height 'H'.The coefficient of restitution be C.
Now,C=v_1/u.Therefore,v_1=Cu
This v_1 is the speed with which it bounces.Then,it strikes the floor again.
And again,C=v_2/v_1

v_2= C.v_1 = C^2 u
Similarly,v_3= C^3u
v_4=C^4u and so on.

Suppose that the ball comes to rest after bouncing up n times.
Therefore,
v_n = 0
C^n.u = 0
And this is only possible when n tends to infinity.In other words,it never comes to rest.But,practically,this is not the case.How come?
 
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First of all coefficient of restitution is
C=v/u simply in case of bouncing of a rigid ball on a rigid surface.Not , C=(v-1)/u.
Then, also this paradox arises as you mentioned .
we must not forget that we apply Newton's laws in some idealized cases. And this application may seem to be miraculous some time. But as we go into detail, not neglecting many phenomenons, then gradually we come close to physical reality.
In this case of bouncing object , we assumed it to be point particle. If we consider it to big enough ,then also bouncing height will never be equal to zero mathematically.But, the height achieved after several bouncing will be so small that we will not be able to distinguish it from
atomic motions.
 
No,its no v-1, its v_1.I don't know how to use subscripts on mobile.v_1 is the velocity with which the ball bounces up after striking the floor 1st time.
v_2 2nd time
v_n nth time
 
Then also logic is same,isn't it.
 
Yeah,just want to make it clear!
 

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