Determining Rotational Inertia of Mass Points?

I have been trying to determine the relationship between masses on a rotating frame, radii of a second mass, and a hanging mass causing angular acceleration on a device I'll attach to a reply question.

The formula we were given to determine rotational inertia was I=radius of hub * acceleration*force (hanging mass x gravity).

They've been coming out fairly consistent, but I'm stuck on trying to find the use and equation of additional masses. Thanks for any help.

Question

Determining Rotational Inertia of Mass Points?

I have been trying to determine the relationship between masses on a rotating frame, radii of a second mass, and a hanging mass causing angular acceleration on a device I'll attach to a reply question.

The formula we were given to determine rotational inertia was I=radius of hub * acceleration*force (hanging mass x gravity).

They've been coming out fairly consistent, but I'm stuck on trying to find the use and equation of additional masses. Thanks for any help.

anonymous · Answer

This is the device, with the additional masses being the end piece on the top arm. That mass is located at the centre, 5cm, 10cm, and 15 cm from the centre.

anonymous · Answer

And if it helps, these are the numbers we had from the experiment.

vincent-lyon.fr · Answer

Rotational inertia of a mass-point $m$ at a distance $L$ from the axis is $mL^2$.