Newton's Third Law: Equal & Opposite Forces?

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Discussion Overview

The discussion revolves around Newton's Third Law of Motion, specifically the interpretation of equal and opposite forces and their implications for balance and acceleration. Participants explore the nuances of how these forces interact in various scenarios, such as walking and the motion of vehicles.

Discussion Character

  • Debate/contested

Main Points Raised

  • Some participants assert that while Newton's third law states that forces are equal and opposite, this does not imply that they are balanced forces, as seen in the context of acceleration in walking or driving.
  • One participant describes the interaction of a person walking, noting that the force exerted downwards on the ground results in forward motion, while the Earth exerts an equal and opposite force.
  • Another participant questions whether equal and opposite forces imply balance, suggesting that they do not because these forces act on different bodies.
  • A later reply clarifies that Newton's second law addresses the concept of net force and acceleration, distinguishing it from the equal and opposite forces described in the third law.

Areas of Agreement / Disagreement

Participants express differing views on whether equal and opposite forces can be considered balanced, with some asserting they cannot due to their action on different bodies. The discussion remains unresolved regarding the implications of these forces on motion and balance.

Contextual Notes

The discussion highlights the need for clarity regarding definitions of balance and the conditions under which forces are considered acting on different bodies. Assumptions about the context of forces and their effects on motion are not fully explored.

Faded Maximus
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Newtons third law states that for every force there is an equal an opposite force. This doesn't mean that these forces are balanced though? Things like cars or people walking can still accelerate so these forces can't be balanced?
 
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When you walk you push down on the ground and it moves you forwards.

At the same time, the Earth pushes back on you and moves backwards.

Equal and opposite.
 
Since they are equal and opposite though, would that imply that they are balanced forces?
 
The proper statement of Newton's third law is:

If body A exerts a force on body B, then body B exerts a force on body A that is equal in magnitude and opposite in direction to the force exerted by body A.

By definition, they are equivalent. Newton's 2nd law deals with accelerations due to a net force.
 
Faded Maximus said:
Since they are equal and opposite though, would that imply that they are balanced forces?

The answer is no because the two forces act on different bodies.
 

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