Find the moment of inertia of this disk help

AI Thread Summary
The discussion revolves around calculating the moment of inertia for a cylindrical disk with an off-center hole. Participants emphasize using the parallel-axis theorem and the method of subtracting the hole from the solid disk to find the solution. There is a focus on the importance of understanding the problem and showing effort in solving it independently. Some users express frustration about timing and the purpose of the forum, highlighting that it is meant for collaborative learning rather than completing assignments. Overall, the conversation underscores the need for active participation and comprehension in tackling physics problems.
Quartz
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Homework Statement



A curcial part of a piece of machinery starts as a flat uniform cylindrical disk of radius R0 and mass M. It then has a circular hole of radius R1 drilled into it. The hole's center is a distance h from the center of the disk. Find the moment of inertia of this disk (with off-center hole) when rotated about its center, C.

Hint: Consider a solid disk and subtract the hole; use parallel-axis theorem.

Homework Equations


L=IA


The Attempt at a Solution



I spent hours on paper with no end, google "chicken scratch" for proof.
 
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… one step at a time …

Quartz said:
Hint: Consider a solid disk and subtract the hole; use parallel-axis theorem.

Hi Quartz! :smile:

When you're confused, just go one step at a time …

First step … what is the parallel-axis theorem? :smile:
 
Thanks!

wow great help! this forum is the bestest!
so you mean I pretend it's a solid and then subtract the drilled hole?
then with the theorem and some substitution i can get the answer!?
wow great, thanks so much.
too bad i handed this homework in days ago.
but thank god you could explain it so nicely.
Borat: NOT.
my teacher showed it to me, but whatever.

you people, what's the point of this forum?
 
Quartz said:
too bad i handed this homework in days ago.
…
you people, what's the point of this forum?

The point of this forum is not to do your homework for you.

This is a cooperative forum … we help you to do the work yourself. :smile:

As rohanprabhu previously pointed out to you:
rohanprabhu said:
you need to show some efforts from your side in solving this problem before we can provide you any help with this question.

And if you handed in the work days ago, why did you ask us only 14 hours ago?
 
wans't my original post "04.10.08, 09:32"?
and I got help from my teacher so there.
 
Quartz said:
wans't my original post "04.10.08, 09:32"?

erm … no … your original post, #1 above, was "yesterday" (that's 04.12
08) at 08.45, London time (same day, 03.45 New York time).
 

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