Can gravitational force be reactive?

AI Thread Summary
The discussion centers on the application of Newton's third law of motion, particularly regarding gravitational forces between the Earth and the Moon. It questions whether the gravitational attraction can be considered a reaction force and if action and reaction forces must be of the same nature. Participants argue that while gravitational forces exist in pairs, the nature of these forces—gravitational versus electromagnetic—may complicate the interpretation of Newton's law. The conversation also touches on the concept of inertia and whether it can be classified as a separate force in this context. Ultimately, the dialogue emphasizes the need for clarity in understanding the relationships between different types of forces as defined by classical physics.
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If Earth attracts the Moon with gravitational force, then according to 3,rd Newton's law the Moon attracts the Earth with the same but opposite force. But what if someone argues that the Moon attracts the Earth anyway due to its own gravitation, can we really say that it's the reaction force?
Another example: You push the car. Here the action force is electromagnetic. The car pushes you back and it's the reaction force, electromagnetic. So it seems that action and reaction must be the forces of the same nature. But what if someone uses the same argument here, and explains the third Newton law like this:
When you push the car, the action force is electromagnetic. Because of the inertia of the car, it oposes the push and you feel the reaction force. Thus, here the reaction force is the force of inertia and is therefore of different nature than the action force.
So two questions:
1 Is this explanation of the 3.rd Newtons law better than the first one?
2 Can gravitational force really be force of reaction?
 
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Lookup some numbers (google calculator). Calculate the force of the moon's gravity attracting the earth. Then calculate the force of the Earth's gravity attracting the moon. Learn by exploration. It's not a matter of whether it is the reaction force. The reaction law just asserts that there will be such a force.
 
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xAxis said:
If Earth attracts the Moon with gravitational force, then according to 3,rd Newton's law the Moon attracts the Earth with the same but opposite force. But what if someone argues that the Moon attracts the Earth anyway due to its own gravitation, can we really say that it's the reaction force?
Another example: You push the car. Here the action force is electromagnetic. The car pushes you back and it's the reaction force, electromagnetic. So it seems that action and reaction must be the forces of the same nature. But what if someone uses the same argument here, and explains the third Newton law like this:
When you push the car, the action force is electromagnetic. Because of the inertia of the car, it oposes the push and you feel the reaction force. Thus, here the reaction force is the force of inertia and is therefore of different nature than the action force.
So two questions:
1 Is this explanation of the 3.rd Newtons law better than the first one?
2 Can gravitational force really be force of reaction?

In what sense electromangetic are u talkin in refrence to friction which is produced due to electromagtic intraion b/w two surface.
Now Newtons 3rd law is not a general term it always exists in pairs as you know. Gravitaion is again not a general term it also exsists in pair consider this in clasical physics a planet is there in an insolated space and think that there is no other planet or star think it is completely isolated. what could you think what will be its stabiltiy and gravitation
 
xAxis said:
When you push the car, the action force is electromagnetic. Because of the inertia of the car, it oposes the push and you feel the reaction force. Thus, here the reaction force is the force of inertia and is therefore of different nature than the action force.
I have not heard of a 'force of inertia' as such. In the example you have given, both force pairs are electromagnetic in nature.
 
I'd like to know if action and reaction must be forces of the same nature according to Newton.
When the object falls to Earth, we say it falls (accelerates) due to gravitational force. If you push an object it accelerates due to which force?
 
xAxis said:
I'd like to know if action and reaction must be forces of the same nature according to Newton.
Yes.
When the object falls to Earth, we say it falls (accelerates) due to gravitational force.
OK. And the 3rd law pair to the force of the Earth's gravitational force on the object is the object's gravitational force on the Earth.
If you push an object it accelerates due to which force?
You exert a contact force on the object, which is fundamentally electromagnetic; the object, per Newton, exerts an equal but opposite contact force on you, also electromagnetic.
 
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