Moment of inertia, double integral

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SUMMARY

The discussion centers on the calculation of the moment of inertia using double integrals, specifically addressing the confusion between the moment of inertia about the y-axis and the origin. The participants clarify that the moment of inertia is defined with respect to an axis of rotation, not a point, and emphasize the importance of using the correct formula from the provided resource on polar moment of inertia. The link shared contains relevant equations that are crucial for solving the problem presented.

PREREQUISITES
  • Understanding of double integrals in calculus
  • Familiarity with the concept of moment of inertia
  • Knowledge of polar coordinates and their applications
  • Ability to interpret physical applications of mathematical concepts
NEXT STEPS
  • Study the derivation and applications of the moment of inertia formulas
  • Learn how to apply double integrals in calculating moments of inertia
  • Explore the differences between polar moment of inertia and other forms
  • Review examples of physical applications of double integrals in engineering
USEFUL FOR

Students in physics or engineering courses, educators teaching mechanics, and anyone interested in the mathematical foundations of rotational dynamics.

Feodalherren
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Homework Statement


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Homework Equations





The Attempt at a Solution


For part B, why is he using the formula for the moment of inertia about the y-axis? Why isn't he using the formula for the moment of inertia about the origin?

http://www.math24.net/physical-applications-of-double-integrals.html

The formula that I'm referring to is the "polar moment of inertia" in this list.
 
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We can't read any problem statement and relevant equations in you post.
What's the question?

Note that a moment of inertia is always defined with respect to an axis (of rotation).
There is nothing like a moment of inertia about a point like the origin.
 
You can't see the picture? I can see it :/.

The formulas are in the link.
I don't know what to tell you. The problem is asking for moment of inertia about the origin. The list of integrals also has a formula for "polar moment of inertia".
 

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