Calculating Rotational Inertia for a Section of a Right Circular Cylinder

[brad sue]

Hi,
Please take a look at this:

Calculate the rotational inertia of a section of a right circular cylinder of radius R that subtends an angle of 'theta knot' at the origin when the reference axis is at the origin and perpendicular to the section.

I tried to draw the picture in the attachment.
I tried to use the formula I=Integral(R²*dm), with dm =density*dV
where V is the volume. I would like to know if I am in the good direction

Thank you for your help

B

 

[Galileo]

Calculate the rotational inertia of a section of a right circular cylinder of radius R that subtends an angle of 'theta knot' at the origin when the reference axis is at the origin and perpendicular to the section.

Lol, isn't it 'theta naught'? As in \theta_0?

I=\int_V R^2\rho dV
is always correct. You should go to cilindrical coordinates for this problem.

 

[brad sue]

Help

Hi I am still stuck with with problem of inertia . please can someone help me.
Can you give me more suggestions
Brad

 

[Euclid]

If I understand the question correctly, maybe this will help
\int_V R^2\rho dV =\rho \int_V r^2 r dr d\phi dz