Does a rotating rigid body has single angular velocity.

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Discussion Overview

The discussion centers on the nature of angular velocity in the context of rotating rigid bodies, specifically whether a rigid body has a single angular velocity or if it varies depending on the point of reference from which it is measured. The scope includes theoretical considerations of rotational motion and the implications of angular velocity as a vector quantity.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant suggests that angular velocity must be defined from a specific point, arguing that a rotating particle can exhibit different angular velocities when measured from different reference points.
  • Another participant asserts that angular velocity is always considered about the rotation axis and is a vector that points along this axis, referencing the right-hand rule for its direction.
  • A question is raised about whether it is meaningful to discuss the angular velocity of a body from points that do not lie on the axis of rotation.
  • A later reply indicates that while one can consider another parallel axis and circular translation, the angular velocity remains the same.

Areas of Agreement / Disagreement

Participants express differing views on the definition and measurement of angular velocity, with no consensus reached on whether angular velocity can vary based on the reference point.

Contextual Notes

There are assumptions regarding the definition of angular velocity and its dependence on the chosen axis of rotation, which remain unresolved in the discussion.

Ahsan Khan
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Hello all,

First of all I want to mention what believe or result of concepts, do I hold about rotational motion especially about the angular velocity. I assume that unlike velocity angular velocity has to worked out from some point. I will begin with particle for this I assume that the question of finding the angular velocity of a particle is meaningless unless it is told from what point angular velocity has to be worked since what I think is that a given rotatating particle can have different angular velocities when calculated from different points. Correct me if i am wrong here.I am holding also the similar view for rigid body that when a rigid body is rotating about some axis then the angular velocity of all points on body will be the same when the angular velocity is observed from the point of axis of rotation. But the about some points exist on other than axis of rotation the different points of the rigid body will have in general different angular velocities.

Are these my views consistent with the reality?

Regards
 
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ovais said:
Regards
The angular velocity is always taken about the rotation axis. Also, the angular velocity is a vector that points along the axis of rotation - the right-hand rule is used:
Angular velocity is the rate of angular displacement about an axis. Its direction is determined by right hand rule. According to right hand rule, if you hold the axis with your right hand and rotate the fingers in the direction of motion of the rotating body then thumb will point the direction of the angular velocity.
 
.Scott said:
The angular velocity is always taken about the rotation axis.

Do you mean we can't or atleast don't talk about angular velocity of body about points that do not exist on axis of rotation?
 
ovais said:
Do you mean we can't or atleast don't talk about angular velocity of body about points that do not exist on axis of rotation?
You can assume another parallel axis plus circular translation, but the angular velocity will be still the same.
 

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