Is Force Ever a Function of Acceleration in Classical Mechanics?

AI Thread Summary
In classical mechanics, forces are typically not expressed as direct functions of acceleration due to dimensional inconsistencies. The discussion highlights that while acceleration may change over time, forces generally depend on position, velocity, and time rather than acceleration alone. A specific example mentioned involves a string attached to a ball, where the force exerted by the ball on the string can be related to its acceleration. However, the consensus is that force is not commonly measured or plotted against acceleration in standard practice. Overall, the professor's assertion emphasizes the conventional approach to analyzing forces in dynamics.
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.
 

Thread 'Is calling fictitious forces "not real" just about terminology?'

Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
View full post »

Thread 'Derivation of Hamilton's Principle: Questions'

I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
View full post »

Similar threads

I Question on analytic mechanics
Replies
3
Views
1K
I Change of coordinates in a potential energy field
Replies
2
Views
1K
I Calculus Question within Lagrangian mechanics
Replies
2
Views
1K
I Lagrangian mechanics - generalised coordinates question
Replies
4
Views
1K
I Help with Goldstein Classical Mechanics Exercise 1.7
Replies
14
Views
2K
Where's my mistake? (Pendulum with gravity)
Replies
7
Views
1K
I Adding total time derivative to Lagrangian/Canonical Transformations
Replies
2
Views
264
I Effective mass from the Lagrangian
Replies
3
Views
2K
I How did Hamilton derive the characteristic function V in his essay?
Replies
3
Views
1K
I Types of symmetries in Lagrangian mechanics
Replies
3
Views
2K

Hot Threads

Recent Insights

Back
Top