Newton's Third Law: Why Is There Motion?

Click For Summary

Discussion Overview

The discussion revolves around the implications of Newton's Third Law of Motion, particularly addressing the question of why motion occurs if the law states that for every action there is an equal and opposite reaction. Participants explore the relationship between forces and motion, considering both theoretical and conceptual aspects.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants question the interpretation of Newton's Third Law, asking why motion occurs if equal and opposite forces are at play.
  • Others clarify that the forces described by Newton's Third Law act on different bodies and do not cancel each other out, suggesting that this allows for motion.
  • One participant notes that during a collision between two blocks, the forces they exert on each other are equal and opposite, yet motion occurs due to inertia.
  • Another point raised is that while the law implies no motion of the center of mass of a system, individual objects can still exhibit motion.

Areas of Agreement / Disagreement

Participants express differing views on the implications of Newton's Third Law regarding motion. There is no consensus on whether the law inherently prevents motion or how it relates to the motion of individual objects versus the center of mass.

Contextual Notes

Some assumptions about the conditions under which Newton's Third Law applies are not fully explored, and the discussion does not resolve the complexities of motion in systems involving multiple bodies.

lewis198
Messages
95
Reaction score
0
I was wondering, if Newton's third law is true why is there motion?
 
Science news on Phys.org
lewis198 said:
I was wondering, if Newton's third law is true why is there motion?
Why do you think that Newton's 3rd law would prevent motion? Note that the equal and opposite forces mentioned in Newton's 3rd law act on different bodies, thus they don't cancel--if that's what you're thinking.
 
According to the third law.if two blocks collide each other. they apply force on each other by equation F=-F.
note:when block hits another block. it moves when it collides with Inertia.
 
Newton's third law includes reaction forces. When an object is accelerated, it reacts with an opposing force equal in magnitude to the force accelerating it.
 
lewis198 said:
I was wondering, if Newton's third law is true why is there motion?

actually
It says there is no motion of their centre of mass.

But there IS motion of the the 2 individual objects. Obviously.
 

Similar threads

Graduate The violation of Newton's third Law
  • · Replies 28 ·
Replies
28
Views
4K
Graduate Newton's third law is frame independent?
  • · Replies 9 ·
Replies
9
Views
3K
High School Violation of Newton's third law
  • · Replies 7 ·
Replies
7
Views
3K
Graduate Exceptions to the Laws of Physics: Newton's Third Law
  • · Replies 10 ·
Replies
10
Views
7K
High School Why Does a Ball Bounce Back from a Wall But Not from Sand?
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Prediction of Newton's third law
  • · Replies 6 ·
Replies
6
Views
2K
High School Trouble understanding Newton's Third Law in Pulleys
  • · Replies 7 ·
Replies
7
Views
7K
Undergrad How Does Newton's Third Law Clarify Force and Acceleration Misconceptions?
  • · Replies 24 ·
Replies
24
Views
4K
Undergrad Center of mass, Newton's third law, and rocket thrust
  • · Replies 8 ·
Replies
8
Views
3K
Undergrad Newton's Third Law: Action & Reaction Along the Line Connecting Two Objects
  • · Replies 5 ·
Replies
5
Views
2K