Newton's law of equal/opposite reaction, and bullet impact...

Click For Summary

Discussion Overview

The discussion revolves around Newton's law of equal and opposite reactions in the context of a bullet's impact on a target. Participants explore the mechanics of forces involved during the bullet's acceleration and its subsequent impact, questioning the nature of reaction forces and energy absorption.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant expresses confusion about the absence of a rebounding force against a bullet's impact, questioning why the material being struck does not exhibit an equal reaction force.
  • Another participant argues that the reaction force is indeed present, as it is what stops the bullet upon impact, suggesting that without this force, the bullet would continue moving at constant velocity.
  • A participant reiterates their initial confusion, emphasizing that they observe no equal opposing force against the bullet during impact.
  • One participant acknowledges the existence of a reaction force but reflects on the misconception of expecting it to reverse the bullet's direction.
  • Another participant seeks methods to absorb kinetic energy without broad transmission or to negate impact forces entirely, prompting a request for clarification on this idea.

Areas of Agreement / Disagreement

Participants do not reach a consensus; there are competing views regarding the nature and perception of reaction forces during a bullet's impact, with some asserting their presence and others questioning their observable effects.

Contextual Notes

There is uncertainty regarding the definitions of forces involved in the impact scenario, and assumptions about the nature of materials and their responses to bullet impacts are not fully explored.

davidsirmons
Messages
9
Reaction score
1
When fired, a slug's acceleration down a barrel produces an equal backward force. I get that.
What I DON'T get, is why there is no rebounding force counter to a slug's impact by the material being struck? The material/molecules simply get impacted and pushed via the force generated. Why is there no equal reaction going in the opposite direction of the bullet? By all observation, the forces exerted by a slug impact do NOT have equal opposing force against the bullet.
 
Physics news on Phys.org
davidsirmons said:
By all observation, the forces exerted by a slug impact do NOT have equal opposing force against the bullet.
They do. That's what stops the bullet once it hits the target. Without a reaction force supplied by the material being struck, the bullet would just continue ahead with constant velocity.
 
davidsirmons said:
When fired, a slug's acceleration down a barrel produces an equal backward force. I get that.
What I DON'T get, is why there is no rebounding force counter to a slug's impact by the material being struck? The material/molecules simply get impacted and pushed via the force generated. Why is there no equal reaction going in the opposite direction of the bullet? By all observation, the forces exerted by a slug impact do NOT have equal opposing force against the bullet.

What makes you say that? The bullet is stopped or slowed by the target by reaction forces.

If you mean a paper target, both action and reaction are slight.
 
The more I thought about it, the more I realized that indeed a reaction is taking place, though I was thinking double the reaction (i.e. reversing the bullet direction)
Am looking for a way to either absorb kinetic energy entirely without broad transmission, or some other way to negate to 0 impact forces.
 
  • Like
Likes   Reactions: Xilus
davidsirmons said:
Am looking for a way to either absorb kinetic energy entirely without broad transmission, or some other way to negate to 0 impact forces.

I don't understand what that means. Please state your question more clearly.
 

Similar threads

Undergrad Newton's Third Law: Action & Reaction Along the Line Connecting Two Objects
  • · Replies 5 ·
Replies
5
Views
2K
High School Newton's Third Law in space
  • · Replies 20 ·
Replies
20
Views
2K
Undergrad Question about Momentum vs. Kinetic Energy vs. Deforming In Collisions
  • · Replies 2 ·
Replies
2
Views
2K
High School Are frictional forces action forces or reaction forces?
  • · Replies 14 ·
Replies
14
Views
2K
High School Action-reaction of a sailing boat and wind
  • · Replies 8 ·
Replies
8
Views
1K
High School Newton's third law (equal and opposite force)
  • · Replies 40 ·
2
Replies
40
Views
4K
Undergrad How Does Mass Influence the Reaction in Newton's 3rd Law of Motion?
  • · Replies 9 ·
Replies
9
Views
2K
High School Newton's 3rd Law interactions with 2nd and 1st Law Partners
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad How a rigid body causes a reaction force?
  • · Replies 61 ·
3
Replies
61
Views
5K
Undergrad Reaction force of and its relation to normal force and friction
  • · Replies 20 ·
Replies
20
Views
4K