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Q & A: Moment of Inertia

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Most recent answer: 05/16/2013
Q:
When we calculate the moment of inertia of an object we get a certain value with units kg m^2.What is the meaning of that value.What does it explain about the body\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'s properties.
- Prudhvi Raj (age 16)
Machilipatnam,Andhra Pradesh,India.
A:
The moment of inertia is a resistance to rotation due to a twisting torque,  similar to mass being  a resistance to acceleration due to a force.   If you calculate it, using Newton\'s Laws, you find you have to take into account the separation of the mass distribution with respect to the rotation axis, as well as the total mass.  The result is that the dimension of mass enters once and that of length enters twice, thus the factor of Kg meter2 in the dimensional formula.  There is a nice Wikipedia article that explains it:      

LeeH

(published on 05/16/2013)

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