Interesting (atleast to me :p)

Moment of Inertia of:

Ring = mr² = Hollow Cylinder

Disc = mr²/2 =Solid Cylinder

Just elongate the ring in the direction of the axis of rotation and you'll get a hollow cylinder.

Just elongate the disc in the direction of the axis of rotation and you'll get a solid cylinder.

Why doesn't MoI of a cylinder depend on it's length?

4 Answers

because it jsut depend on distribution of mass around axis...

and U can say it depends on length or say doesn't depend on length... depends on waht is given mass or density...

ya, but is distribution of mass around axis of rotation same for both disc and solid cylinder?

yes same...
both circular around it...solid one...

it does depend indirectly as ull observe that either mass inc or density dec

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