• Support PF! Buy your school textbooks, materials and every day products Here!

Find the moment of inertia of this disk help

  • Thread starter Quartz
  • Start date
5
0
1. 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.

2. Homework Equations
L=IA


3. The Attempt at a Solution

I spent hours on paper with no end, google "chicken scratch" for proof.
 

Answers and Replies

tiny-tim
Science Advisor
Homework Helper
25,789
249
… one step at a time …

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:
 
5
0
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?
 
tiny-tim
Science Advisor
Homework Helper
25,789
249
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:
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?
 
5
0
wans't my original post "04.10.08, 09:32"?
and I got help from my teacher so there.
 
tiny-tim
Science Advisor
Homework Helper
25,789
249
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).
 

Related Threads for: Find the moment of inertia of this disk help

Replies
2
Views
3K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
1
Views
13K
  • Last Post
Replies
10
Views
3K
  • Last Post
Replies
7
Views
3K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
11K
  • Last Post
Replies
2
Views
3K
Top