How do action reaction force pairs arise?

In summary, the reason for action-reaction force pairs to arise is due to the principle of Newton's Third Law, which states that for every action, there is an equal and opposite reaction. This is considered to be a fundamental principle and cannot be proven. While some forces may not require physical contact, such as gravity, they still follow the concept of action-reaction pairs. Energy and momentum conservation can also be used to explain force pairs, but the Newton's Third Law is typically seen as the more fundamental explanation.
  • #1
echolett
1
0
Hi guys,

What is the reason for action-reaction force pairs to arise?
Is it a consequence of electrostatic repulsion due to interaction of the 2 bodies, or can it be explained using energy conservation or momentum conservation.

Thanks!
 
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  • #2
echolett said:
What is the reason for action-reaction force pairs to arise?
It's an axiom or postulate that is just assumed to be self-evident and true. I'm not sure there's a way to prove it. Almost all forces invoved some type of reaction if you look at a situation from a large enough scale, and consider things like how much the Earth is affected by a car acclerating on it's surface.

In some cases, a Newton 3rd law pair doesn't require physical contact, such as gravity, where the third law pair is the equal and opposing attractive force on each body in a two body system.
 
  • #3
You could derive force pairs from momentum conservation of arbitrary pairs of objects, but we tend to think of actio = reactio as being more fundamental.
 

1. What is an action-reaction force pair?

An action-reaction force pair is a pair of forces that occur simultaneously and act in opposite directions. The two forces have equal magnitudes and are exerted by two different objects upon each other.

2. How do action-reaction force pairs arise?

Action-reaction force pairs arise due to Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. This means that whenever an object exerts a force on another object, the second object will exert an equal and opposite force back on the first object.

3. Can action-reaction force pairs cancel each other out?

No, action-reaction force pairs cannot cancel each other out because they act on two different objects. While the forces may be equal in magnitude and opposite in direction, they are acting on separate objects and therefore cannot cancel each other out.

4. Do action-reaction force pairs always have the same effect?

No, action-reaction force pairs do not always have the same effect. While the forces are equal and opposite, the effects they have on the objects may differ depending on their masses and accelerations. For example, a small object may experience a greater acceleration from a force than a larger object.

5. Can action-reaction force pairs exist without motion?

Yes, action-reaction force pairs can exist without motion. According to Newton's first law of motion, an object will remain at rest or in motion with a constant velocity unless acted upon by a net external force. This means that even if an object is not in motion, it may still be experiencing action-reaction force pairs.

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