Moment of Inertia Explained: Definition & Examples

AI Thread Summary
The moment of inertia is defined as the ratio of torque (moment of force) to angular acceleration, similar to how mass relates force to linear acceleration. It quantifies the resistance of an object to changes in its rotational motion. Essentially, while mass indicates how hard it is to push an object, the moment of inertia indicates how hard it is to rotate it. Understanding this concept is crucial in angular mechanics. For further examples, resources like the PF library or Wikipedia can provide additional insights.
michaelknight
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what is a moment of inertia? I know it's used for angular mechanics (like angular velocity and stuff like that), but what is a moment of inertia? A good definition with some examples would help tremendously. Thank you much in advance :)
 
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hi michael! :smile:

just as the mass (or inertia) of a body is the ratio between any force on it and its (linear) acceleration,

so the moment of inertia of a body is the ratio between the moment of force (also called the torque) on it and its angular acceleration

in other words: mass (or inertia) tells you how difficult it is to push, while moment of inertia tells you how difficult it is to turn :wink:

(for examples, see the pf library or wikipedia)
 
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