Definition of Parallel-axis theorem

  • Context: Undergrad 
  • Thread starter Thread starter Duane
  • Start date Start date
  • Tags Tags
    Definition Theorem
Click For Summary

Discussion Overview

The discussion revolves around the physical meaning of each term in the parallel-axis theorem, specifically the equation I = I_com + Mh^2. Participants explore the definitions and implications of the terms involved in the theorem.

Discussion Character

  • Conceptual clarification

Main Points Raised

  • Some participants clarify that I represents the moment of inertia about an axis a distance 'h' from the center of mass.
  • Others explain that I_com is the moment of inertia about an axis passing through the center of mass, while M denotes the mass of the object and h is the distance between the two parallel axes.
  • A participant suggests thinking of the theorem as the sum of the moment of inertia about the center of mass and the moment of inertia of the total mass considered as a point mass about the axis in question.

Areas of Agreement / Disagreement

Participants generally agree on the definitions of the terms in the parallel-axis theorem, but there is no explicit consensus on the deeper physical implications of these terms.

Contextual Notes

Some assumptions about the context of the theorem and its applications may not be fully articulated, and the discussion does not delve into specific examples or applications.

Duane
Messages
8
Reaction score
0
What is the physical meaning of each term in the parallel-axis theorem?


I=I com +Mh^2
 
Physics news on Phys.org
Duane said:
What is the physical meaning of each term in the parallel-axis theorem?


I=I com +Mh^2
Not sure what you mean by 'physical' meaning, but:
I = moment of inertia about some axis a distance 'h' from the center of mass
Icom = moment of inertia about some axis (parallel to the other) passing through the center of mass
M = mass of object
h = distance between those two parallel axes

You can think of it as the sum of the moment of inertia about the center of mass and the moment of inertia of the total mass (considered as a point mass) about the axis in question.
 
Duane said:
What is the physical meaning of each term in the parallel-axis theorem?


I=I com +Mh^2
Icom is the moment of inertia of an object about an axis through the centre of mass. I is the moment of inertia of the object about an axis that is parallel to the axis through the centre of mass (com) and separated from it by a distance h. M is the mass of the object.

AM
 
Thanks, that helped a lot!
 

Similar threads

Undergrad Explanation of parallel axis theorem
  • · Replies 2 ·
Replies
2
Views
1K
High School When is the parallel axis theorem not appliable?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Resolve moment of inertia at an angle
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Moment of inertia of human body with limbs at an angle
  • · Replies 12 ·
Replies
12
Views
2K
Parallel Axis Theorem Not Working
  • · Replies 28 ·
Replies
28
Views
2K
Graduate Is angular momentum taken about a point or an axis?
  • · Replies 17 ·
Replies
17
Views
3K
Undergrad Is Mechanical Energy Conservation Free of Ambiguity - follow up
  • · Replies 77 ·
3
Replies
77
Views
6K
Undergrad Conservation of energy in rotating bodies
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Intuition Behind Intermediate Axis Theorem in an Ideal Setting
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Liouville's Theorem and Poincare Recurrence Theorem
  • · Replies 3 ·
Replies
3
Views
2K