Why Can the Center of Mass Lie Outside an Object's Surface?

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Discussion Overview

The discussion revolves around the concept of the center of mass and why it can lie outside the surface of an object. Participants explore scenarios and examples that illustrate when the center of mass is located inside or outside an object's boundaries, including non-spherical shapes and specific examples like a donut.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants inquire about the conditions under which the center of mass can be outside the surface of an object, seeking explanations and examples.
  • One participant suggests that in non-spherically symmetric objects, such as two equal balls touching, the center of mass can lie between them, indicating that shape influences the center of mass location.
  • Another participant introduces the example of a donut to question where its center of mass lies, further exploring the concept.
  • There is a general request for clarification on the criteria that determine whether the center of mass is inside or outside an object.
  • A later comment raises a separate question about the nature of averages, indicating a potential meta-discussion on mathematical concepts.

Areas of Agreement / Disagreement

Participants express curiosity and seek clarification, but there is no consensus on the specific conditions or examples that determine the location of the center of mass.

Contextual Notes

Participants have not fully defined the terms or provided a comprehensive framework for understanding the center of mass in various geometries, leaving some assumptions and conditions unresolved.

Who May Find This Useful

This discussion may be of interest to those studying physics concepts related to mechanics, particularly in understanding the implications of shape and symmetry on the center of mass.

pras_quantum
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can some one explain me why,center of mass of an object can lie outside the surface of the object also?
 
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Why don't you explain why you think it cannot?
 
actually i want to know when will it lie inside or outside the objects..so please explain.
 
pras_quantum said:
can some one explain me why,center of mass of an object can lie outside the surface of the object also?

If the body is not so spherically symmetric, for example, two equal balls touching, then the center of inertia is between them (at the touching point). If there are three balls, the center of inertia will be at the geometrical center of this figure. So it is possible if the body is not spherically symmetric but has a complicated form.
 
pras_quantum said:
actually i want to know when will it lie inside or outside the objects..so please explain.
Consider a donut (with a hole in the middle). Where is its center of mass?
 
thank you people for helping me...
 
Just another comment:

If you take the average of 10 (or some other quantity) numbers, pras_quant, must the average of those numbers be one of those numbers?
 

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