Is Force Ever a Function of Acceleration in Classical Mechanics?

  • Context: Undergrad 
  • Thread starter Thread starter GreenLRan
  • Start date Start date
  • Tags Tags
    Acceleration Force
Click For Summary

Discussion Overview

The discussion centers on the relationship between force and acceleration in classical mechanics, particularly whether force can be expressed as a function of acceleration. Participants explore the implications of this relationship in the context of dynamics and reaction forces.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant notes that their professor stated you will never find a force that is a function of acceleration, prompting a question about the reasoning behind this claim.
  • Another participant suggests that forces typically vary with time, implying that a direct functional relationship like F=2a²+a+3 would not be dimensionally valid.
  • Some participants propose that reaction forces, such as those in a system with a string and a ball, could be considered a function of the ball's acceleration.
  • A later reply reiterates the idea of reaction forces, suggesting that while forces may not be typically measured against acceleration, they can still be related in specific contexts.

Areas of Agreement / Disagreement

Participants express differing views on whether force can be a function of acceleration, with some supporting the idea of reaction forces while others uphold the professor's statement. The discussion remains unresolved.

Contextual Notes

There are limitations regarding the definitions of force and acceleration, as well as the context in which these relationships are considered. The discussion does not resolve the dimensional validity of proposed functional forms.

GreenLRan
Messages
59
Reaction score
0
In class today, my professor said that you will never find a force that is a function of acceleration.

Why is this?


M\ddot{x}(t) = F(x,y,z,\dot{x},\dot{y},\dot{z},t)
M\ddot{y}(t) = F(x,y,z,\dot{x},\dot{y},\dot{z},t)
M\ddot{z}(t) = F(x,y,z,\dot{x},\dot{y},\dot{z},t)

This is in a classical mechanics / dynamics course
 
Physics news on Phys.org
Usually forces vary with time, because acceleration would vary with time. I think he meant that you would not find a function such that F=2a2+a+3 as that would not work dimensionally.
 
What about a reaction force? For example a string attached to a ball and accelerating the ball, the force the ball exerts on the string is a function of the acceleration of the ball.
 
rcgldr said:
What about a reaction force? For example a string attached to a ball and accelerating the ball, the force the ball exerts on the string is a function of the acceleration of the ball.

Well that is what I am saying, I think your professor meant that you would not usually measure force with acceleration or well plot force against acceleration.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 41 ·
2
Replies
41
Views
4K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
1K