Newton third law and finding the reverse distance

In summary, the conversation discusses a physics problem involving a ball moving towards an air source and reversing its direction once it reaches a certain point. The exact distance the ball will move in the opposite direction cannot be determined, but it will continue to move backwards indefinitely as long as there are no external forces to stop it. The conversation also mentions the role of friction in the problem and the importance of understanding the underlying physics rather than relying on numerical examples.
  • #1
abdi1
7
0
hi am new here ... and sorry for my weak English
i have a question and a problem in physics that i need to know it's solution
i will give you the main idea without numbers and you can assume any numbers
that you find it suitable for the problem...

the problem say: if a small ball is moving toward an air source that pump the air toward the ball ...the ball will not be affected by the power of the air source until it reach a certain point and then it will reverse it's direction ...
i need to know the distance that the ball move backward based upon Newton third law
 
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  • #2
The ball will always be affected by the air source, it will move backward indefinitely as time approaches infinity. The only distance you could calculate precisely is the point at which it reverses direction.
 
  • #3
zhermes said:
The ball will always be affected by the air source, it will move backward indefinitely as time approaches infinity. The only distance you could calculate precisely is the point at which it reverses direction.

thanks for ur replay...look at the pic...if the ball is far enogh from the air source...and moveing toward it ...the ball will resist the power of the air source for a while or for a distance until the air source powr become stronge enoght to prevent the ball from keep going toward and make it reverse it's movment...then we have reaction...i need to know the distance that the ball will move in the opposite direction.
 

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  • #4
first answer me something, if i push a ball on a surface (assumed to be ideal without friction), then can u determine the distance it will travel before it stops?
u definitely cant, so is the answer for ur qs! the ball travels backwards to infinity

there might be some additional info that u might have missed in the question!
 
  • #5
zhermes said:
The ball will always be affected by the air source, it will move backward indefinitely as time approaches infinity. The only distance you could calculate precisely is the point at which it reverses direction.

hi
sorry for late replay but my internet connection was disconnect

could u please show me the calculation ?
or any other member could do that and thanks in advance


Mandeep Deka said:
first answer me something, if i push a ball on a surface (assumed to be ideal without friction), then can u determine the distance it will travel before it stops?
u definitely cant, so is the answer for ur qs! the ball travels backwards to infinity

there might be some additional info that u might have missed in the question!

thanks for u ...may be because am not good in physics so i didnt put the question and the case in good words...but that is all informations that i have...
 
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  • #6
There is no need for a calculation. You can deduce it from Newton's first if you want to. The air pump will decelerate the ball going to the right and then accelerate it to go to the left. As long as there is nothing to stop it, e.g. another external force it will continue to go forever.
Note: In this problem friction plays a role. But the pressure from the air pump will keep the ball in motion.
 
  • #7
hi...thanks for ur reply betel
could u please give me a hypothetical example with a numbers
am in a need for numerical example if u could help me
 
  • #8
If you understood what we said you should be able to find some numbers yourself.

If you need explicit numbers for your homework we will not do them for you here. We can help you understand the physics behind it but we will not present you with the solution.
 
  • #9
betel said:
If you understood what we said you should be able to find some numbers yourself.

If you need explicit numbers for your homework we will not do them for you here. We can help you understand the physics behind it but we will not present you with the solution.

:smile: :smile: :smile:
hi and thanks...it's not a homework it's just a practical case that am thinking about...bay the way i finished study and forgut about homeworks since 2001, until u remind me about that days :smile:

if any member would like to help me i will appreciate
 
  • #10
So what do you actually want to know? If you want exact numbers you need to give an exact setup.
 
  • #11
my problem is that am a practical in thinking or in acting
i don't like theories or just a word of description so i like a numerical example that help me and show the case in numbers
that all
 
  • #12
For the question as you stated it in this setup the answer is infinity regardless of any other numbers.
 
  • #13
ok thanks betel...
i will think agine about my setup and try to change it and post agine
 

FAQ: Newton third law and finding the reverse distance

What is Newton's Third Law of Motion?

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object will exert an equal force in the opposite direction.

How does Newton's Third Law apply to finding the reverse distance?

When using Newton's Third Law to find the reverse distance, we must consider the forces acting on both objects in the system. The force exerted by one object on the other will be equal in magnitude but opposite in direction to the force exerted by the second object on the first. By using this relationship, we can calculate the distance between the two objects.

Can Newton's Third Law be applied to all types of forces?

Yes, Newton's Third Law applies to all types of forces, whether they are contact forces (such as a push or pull) or non-contact forces (such as gravitational or magnetic forces). The key is to identify the two objects involved in the interaction and determine the direction and magnitude of the forces they exert on each other.

What is the significance of Newton's Third Law in the study of motion?

Newton's Third Law is crucial in understanding how objects move and interact with each other. It helps us predict the motion of objects and explains why objects move the way they do. It also plays a vital role in fields such as engineering and physics, where it is used to design and analyze various systems and structures.

Can Newton's Third Law be violated?

No, Newton's Third Law is a fundamental principle of physics and cannot be violated. In any interaction between two objects, the forces exerted by each object on the other will always be equal and opposite. If it appears that this law has been violated, it is likely due to external factors that were not considered or measured accurately.

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