A quick question about friction and applied force

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Homework Help Overview

The discussion revolves around the concepts of friction and applied force, particularly in the context of Newton's laws of motion. Participants explore the conditions under which an object remains at rest or moves, focusing on the relationship between static friction and applied force.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the implications of friction being greater than applied force, questioning whether this results in zero acceleration or a backward acceleration. They also explore the conditions for balanced forces and the transition from static to kinetic scenarios.

Discussion Status

The discussion is active, with participants offering different interpretations of the relationship between applied force and friction. Some clarify that if the applied force is less than static friction, the object does not move, while others suggest that if the object is already in motion, different dynamics apply.

Contextual Notes

Participants are considering scenarios involving static friction and the conditions under which an object is at rest versus in motion. There is an emphasis on the assumptions related to the state of the object (at rest or in motion) and the nature of the forces involved.

pyroknife
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if the friction force is larger than the applied force. the object wouldn't move and the acceleration would be 0 right?
 
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If the friction force is larger than the applied force, The net force would move with the force of friction. in essence the Force of friction would become the applied force, the applied force would slow it down (apply friction)

Newtons First Law: if a = 0; F_{applied} = F_{friction} meaning any time acceleration is zero, the forces are balenced and equal each other, if Ff is greater than Fp, e.g. Ff = 60 N, Fp = 50 N

Fnet would be -10N as Fnet = Fp - FF

Fnet = 50N - 60N
Fnet = -10N so it would move and accelerate backwards.
 
Senjai said:
If the friction force is larger than the applied force, The net force would move with the force of friction. in essence the Force of friction would become the applied force, the applied force would slow it down (apply friction)

Newtons First Law: if a = 0; F_{applied} = F_{friction} meaning any time acceleration is zero, the forces are balenced and equal each other, if Ff is greater than Fp, e.g. Ff = 60 N, Fp = 50 N

Fnet would be -10N as Fnet = Fp - FF

Fnet = 50N - 60N
Fnet = -10N so it would move and accelerate backwards.
No. If the applied force to an object is less than the static friction, the object does not move. The applied force will be balanced by an equal and opposite static force.
 
so that means acceleration=0 and not a negative number right?
 
pyroknife said:
so that means acceleration=0 and not a negative number right?
The force is static, hence no motion (i.e. no change in velocity), hence no acceleration.

This assumes an object at rest.


If one can get an object moving, and then the applied force equals the friction force, one can have a constant velocity, but no acceleration.
 

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