Why is There Acceleration Despite Newton's Third Law of Motion?

  • Thread starter Thread starter AllenHe
  • Start date Start date
  • Tags Tags
    Motion
Click For Summary

Homework Help Overview

The discussion revolves around the apparent contradiction between Newton's Third Law of Motion and the occurrence of acceleration in various scenarios. Participants are exploring the nuances of force interactions and the conditions under which acceleration occurs.

Discussion Character

  • Conceptual clarification, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants are questioning how equal and opposite forces can coexist with acceleration, particularly in examples involving pushing objects. They are examining the role of additional forces and the distinction between forces acting on different bodies.

Discussion Status

The discussion is active, with participants providing insights into the nature of forces and acceleration. Some have offered clarifications regarding the application of Newton's laws, while others are exploring the implications of additional forces on the acceleration of a specific mass.

Contextual Notes

There is an emphasis on understanding the forces acting on individual masses, as well as the need to consider all forces involved in a given scenario to fully grasp the resulting motion.

AllenHe
Messages
74
Reaction score
0

Homework Statement


The law states that "Whenever one body exerts a force on another, the second exerts an equal and opposite force on first." But then, why is there acceleration?


Homework Equations





The Attempt at a Solution


If there will be force responding to the first one with equal magnitude, then there won't be any net force.Then why is there acceleration?
 
Physics news on Phys.org
One must keep in mind that the two forces mentioned in Newton's 3rd law act on two different bodies.
 
but, for example. When I push a wall, I will exert a force on the wall, and the wall will exert a force on me.
In another case, when I am pushing a person with 100N, and that person also pushes me with 100N, in opposite direction, then none of us will move. How do you explain that?
 
Consider a person being pushed by me by 100N.
To find whether he will accelerate or not one has to see if there are other forces acting thus contributing to increase or decrease the effect of the !00N that I am applying.
That is to find HIS acceleration one is interested in the forces acting ON HIM and not on me.
 
Oh, so what you are saying is that it's other forces which make the person accelerate, right?
 
What I said was that to find the acceleration on a certain mass, one has to find the forces acting on THAT mass. That is what Newton's 2nd law says.
 

Similar threads

  • · Replies 25 ·
Replies
25
Views
2K
  • · Replies 8 ·
Replies
8
Views
4K
Replies
6
Views
3K
  • · Replies 12 ·
Replies
12
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
55
Views
3K
  • · Replies 14 ·
Replies
14
Views
2K