# Inertia kg*m^4

1. Jul 31, 2016

### Marco884

Hello! :) ..Can you tell me why when I counting inertia the result must by in meters to the fourth power ?!
Why meters to the fourth power ?!. Is there analogical explanation?!

2. Jul 31, 2016

### Kekrozz

You are doing the same operation that you are doing for the "classical inertia moment", mass x distance^2 (Kg m^2), but instead of the mass you are using the area. the logical explanation is that when you are calculating a some sort of geometrical moments you are, always, multiplying a quantity x distance^2 .

3. Aug 1, 2016

### Marco884

On Wikipedia , I found this information...Soo if we do not have the mass we need to
multiply distance in meters in each case of inertia ?

https://zapodaj.net/57ca0a777bb62.png.html

4. Aug 1, 2016

### Kekrozz

I think you are getting confused by the measure unit. The right expression of a moment (mathematic) is
thishttps://en.m.wikipedia.org/wiki/Moment_(mathematics). [Broken]
You can apply this definition because you have already applied the continuous geometrical model (little mass dots forming your body) . If you thereat your body as a statistical distribution of point you can definitely apply the maths on the link (
Your model could also be a perfect distribution).
Finally you can calculate every moment quantity you want, mass, distant (static moment), area (inertia moment), volume(solid moment)... They tell you info about distribution, so about your body.

Last edited by a moderator: May 8, 2017
5. Aug 1, 2016

### Marco884

Really helped me this link, things were quite different than I thought but I still have smal questions :)

Last edited: Aug 1, 2016
6. Aug 1, 2016

### Kekrozz

yes of course

7. Aug 3, 2016

8. Aug 3, 2016

### Kekrozz

Man I don't understand polish....

9. Aug 3, 2016

### Marco884

Hehe .. Static moments = Momenty statyczne
I guess you know the rest.. :)