Is This Scenario Demonstrating Newton's Third Law of Motion?

  • Context: High School 
  • Thread starter Thread starter permapoop
  • Start date Start date
  • Tags Tags
    Laws Newton's laws
Click For Summary

Discussion Overview

The discussion revolves around a scenario involving two individuals, A and B, where person A hits person B, leading to questions about the applicability of Newton's Second and Third Laws of Motion. Participants explore the implications of the forces and accelerations involved in this interaction.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants propose that both Newton's Second and Third Laws apply to the scenario, with the Second Law governing the acceleration of person A after the collision and the Third Law addressing the forces involved.
  • Others argue that Newton's Second Law is relevant only when there is acceleration and a net force, while the Third Law pertains to the forces exerted between the two individuals, independent of net force.
  • A later reply questions the clarity of the original scenario, suggesting that if person A is pushed back more than person B, it could indicate a violation of the Third Law, which states that forces must be equal and opposite.
  • It is noted that if person A moves farther than person B after the collision, this could imply that person A has a lesser mass, as per the implications of the Second Law.

Areas of Agreement / Disagreement

Participants express differing interpretations of the scenario, with no consensus reached on whether the situation demonstrates Newton's Second or Third Law, or both. The discussion remains unresolved regarding the implications of the forces and accelerations involved.

Contextual Notes

There are limitations in the assumptions made about the scenario, particularly regarding the definitions of "gets pushed" and the implications of distance moved versus forces experienced. The discussion does not resolve these ambiguities.

permapoop
Messages
10
Reaction score
0
Let's say there's two people, A and B.

Person A hits person B and person A gets pushed back more than person B does.

Would be that be exhibiting Newton's Third Law of Motion of Newton's Second Law of Motion?
 
Physics news on Phys.org
I think both.
How much A is pushed back and its acceleration after collision is given by II law, and III law says A is affected by its pushing against B.
 
Newtons II law is applied in cases only if there is acceleration( there must be net force available in a direction). Newton III law is applied in cases involving forces(independent of net force).
 
permapoop said:
Let's say there's two people, A and B.

Person A hits person B and person A gets pushed back more than person B does.

Would be that be exhibiting Newton's Third Law of Motion of Newton's Second Law of Motion?

Your language is a little fuzzy. Does "gets pushed" mean "experiences a force"? If so, the situation you describe violates the third law of motion. It says that whenever one body applies a force to a second body, the second body applies a force of the same size but opposite direction on the first body. The pushes in the scenario have to be the same size.

If "gets pushed back more" means that Person A ends up a greater distance from the starting point than Person B, then the Second Law comes into play. Both people start at rest and end up moving, so each accelerated. If Person A moves farther in a given amount of time, he or she experienced a greater acceleration. It follows from the Second Law that he or she has a lesser mass than Person B.
 

Similar threads

High School Newton's Third Law in space
  • · Replies 20 ·
Replies
20
Views
3K
High School Newton's third law (equal and opposite force)
  • · Replies 40 ·
2
Replies
40
Views
4K
High School The application of Newton's laws to fluid equilibrium
  • · Replies 17 ·
Replies
17
Views
2K
Undergrad Stuck in understanding Newton's 3 laws
  • · Replies 18 ·
Replies
18
Views
3K
High School Newton's Third Law Question -- Does the Earth Do Work on Me?
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Extending Newton's laws -- Is the concept of force still defined?
  • · Replies 35 ·
2
Replies
35
Views
5K
High School Newton’s second law as one complete law
  • · Replies 27 ·
Replies
27
Views
2K
High School Action-reaction of a sailing boat and wind
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Acceleration in Newton's second law
  • · Replies 5 ·
Replies
5
Views
3K
High School Are frictional forces action forces or reaction forces?
  • · Replies 14 ·
Replies
14
Views
2K