Rotational and translational equilibrium

Click For Summary

Discussion Overview

The discussion revolves around the concepts of rotational and translational equilibrium, specifically in the context of a ruler placed on a pivot and the effects of applying a force to one side. Participants explore the relationship between moments, linear movement, and equilibrium states.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions whether applying a downward force on one side of a ruler results in linear movement, given the absence of translational equilibrium.
  • Another participant expresses confusion about how equilibrium is relevant when a force is applied, noting that pushing the ruler will change its position.
  • A participant clarifies that applying a force creates a moment that can be clockwise or anticlockwise, but questions the implications for translational equilibrium.
  • Another participant suggests that an upward reaction force at the pivot balances the downward force, implying a state of equilibrium despite the applied force.

Areas of Agreement / Disagreement

Participants express uncertainty about the relationship between applied forces, moments, and equilibrium. There is no clear consensus on how these concepts interact in the scenario described.

Contextual Notes

The discussion does not resolve the assumptions regarding the definitions of equilibrium or the specific conditions under which moments and forces interact in this context.

sgstudent
Messages
726
Reaction score
3
When a ruler is placed on a pivot and I push it down from one side, then there is a moment. But then is there any linear movement? Since there is no translational equilibrium then won't there be a linear motion? Then how does rotational equilibrium come into play here?
 
Physics news on Phys.org
hi sgstudent! :smile:
sgstudent said:
When a ruler is placed on a pivot and I push it down from one side, then there is a moment. But then is there any linear movement? Since there is no translational equilibrium then won't there be a linear motion? Then how does rotational equilibrium come into play here?

i don't understand :redface: …

if you push it, it will change position …

where does equilibrium come into it? :confused:
 
tiny-tim said:
hi sgstudent! :smile:


i don't understand :redface: …

if you push it, it will change position …

where does equilibrium come into it? :confused:

Oh sorry! I meant that when I push one side of a ruler on a pivot then I'll get a moment that is either clockwise or anticlockwise right? But since there only that downwards force acting on it, won't it mean that it does not have translational equilibrium?
 
hi sgstudent! :smile:
(just got up :zzz:)
sgstudent said:
But since there only that downwards force acting on it, won't it mean that it does not have translational equilibrium?

ah!

but nature automatically supplies an upward reaction force at the pivot …

which exactly balances the downwards force! :wink:​
 
Oh, I understand :-) thanks for the help!
 

Similar threads

Undergrad Solving for the trajectory of the center of mass
  • · Replies 1 ·
Replies
1
Views
1K
Graduate KE of off-center impacts in rotating and translating rigid bodies
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Mechanics of an inertial balance
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad How to account for linear momentum in a collision?
  • · Replies 10 ·
Replies
10
Views
1K
Undergrad Confused about the axis of rotation in rotational motion w/o slipping
  • · Replies 10 ·
Replies
10
Views
4K
Graduate Instantaneous center of rotation
  • · Replies 10 ·
Replies
10
Views
3K
Graduate Does rotational motion affect the translational motion?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Velocity transformation between frames rotating relative to one another
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Confusion About Rotational Motion
  • · Replies 19 ·
Replies
19
Views
2K
Undergrad Distinction between translational and rotational energy
  • · Replies 1 ·
Replies
1
Views
2K