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

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In summary, the conversation discusses the concept of coefficient of restitution and its application to a bouncing object. It is explained that according to Newton's laws, the object should continuously bounce up and never come to rest. However, in reality, this is not the case due to the idealized assumptions made in the application of the laws. The conversation also clarifies the notation used and the logic behind it.
  • #1
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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  • #2
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.
 
  • #3
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
 
  • #4
Then also logic is same,isn't it.
 
  • #5
Yeah,just want to make it clear!
 

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

What is the co-efficient of restitution?

The co-efficient of restitution, or COR, is a measure of the elasticity of a collision between two objects. It is a dimensionless number between 0 and 1, where 0 represents a perfectly inelastic collision (no bounce) and 1 represents a perfectly elastic collision (full bounce).

How is the co-efficient of restitution calculated?

The COR is calculated by dividing the relative velocity of the objects after the collision by the relative velocity before the collision. This can be expressed as COR = (V2f - V1f) / (V1i - V2i), where V1i and V2i are the initial velocities and V1f and V2f are the final velocities of the two objects.

What affects the co-efficient of restitution?

The COR is affected by the material properties of the objects involved in the collision, such as their elasticity and surface texture. It can also be influenced by factors such as the angle of impact and the presence of external forces.

What is the significance of the co-efficient of restitution?

The COR is an important measure in the study of collisions and impacts, as it helps to determine the amount of energy transferred during a collision. It is also used in various sports and games, such as billiards and tennis, to ensure fair play and consistent performance of equipment.

How is the co-efficient of restitution used in engineering and design?

In engineering and design, the COR is used to predict the behavior of objects in impact situations and to design structures and materials that can withstand specific levels of impact. It is also used in the development of safety equipment, such as helmets and padding, to minimize the transfer of energy during collisions.

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