Calculating Moment of Inertia help

AI Thread Summary
To calculate the moment of inertia for a flat rectangular plate with length 'l' and width 'w' about an axis parallel to the width, the formula I = bh^3/3 is applicable, where 'b' is the width and 'h' is the height. Users are seeking a complete derivation of this formula, including calculus and integration steps. The parallel axis theorem may also be relevant in this context. The discussion highlights that the area moment of inertia must be adjusted by density for mass calculations. Understanding the moment of inertia of a thin rod about one end can simplify the problem.
paddlewheel99
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How to Calculate Moment of Inertia for a flat rectangular plate of length 'l' & width 'w' with axis of rotation along the width 'w' (the axis of rotation is parrallel to edge of width)
 
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paddlewheel99 said:
How to Calculate Moment of Inertia for a flat rectangular plate of length 'l' & width 'w' with axis of rotation along the width 'w' (the axis of rotation is parrallel to edge of width)

This should help you out:

http://en.wikipedia.org/wiki/Moment_of_inertia

.
 
No actually it is not easy as it looks. After doing a lot of googling, i got the required equation on http://en.wikipedia.org/wiki/List_of_area_moments_of_inertia
the equation is: I = bh^3/3
Can anyone give a link to the complete derivation of this formula or provide it themselve.
With the complete calculus and intergration involved in it.
Also will the parrallel axis theorem have any role in the derivation.
Thank You
 
paddlewheel99 said:
the equation is: I = bh^3/3
Careful... that's the area moment of inertia. (You'd need to multiply by the density.)

What you want is simpler (but equivalent, of course). Hint: Can you find the moment of inertia of a stick (thin rod) about one end? That's the same problem, believe it or not.
 

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