Moment of Inertia: Rules & Usage Guide

AI Thread Summary
The moment of inertia can be calculated using two formulas: I = ∑m r² for point masses and I = ∫ r² dm for continuous mass distributions. The first formula is applicable when dealing with discrete point masses, while the second is used for objects with mass distributed continuously. Continuous mass distributions refer to bodies where mass is spread out over a volume rather than concentrated at specific points. Understanding when to apply each formula is crucial for accurate calculations in physics. For practical examples, refer to the provided Moment of Inertia Examples.
Neon32
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To find Moment of inertia, there are 2 rules:
I = ∑m r2
I= ∫ r2 dm

I don't know when to use the first and when to use the second rule.
 
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Neon32 said:
I don't know when to use the first and when to use the second rule.
The first is useful for point masses; the second, for continuous distributions of mass.
 
Doc Al said:
The first is useful for point masses; the second, for continuous distributions of mass.
what does continuous distributions of mass mean?
 

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