Rotating body moment of inertia

[Ugnius]

Homework Statement

1. When is the moment of inertia of the body is bigger from perspective of the axis , when body is rotating or when it is not?
2. In which case monolitic rod has a bigger moment of inertia: a) on perspective of axis , going horizontaly thought rods center of mass; b) on perspective of axis , going verticaly thought rods center of mass? Why

Relevant Equations

None

I have done some lab work , and now i have to answer some theoretical questions , but i can not find any data about this on the web or atleast i don't know where to search , i will add some pictures of experiment for you to better understand it. I was wondering can someone share their knowledge or papers to help me understand this.

 

[Doc Al]

1. When is the moment of inertia of the body is bigger from perspective of the axis , when body is rotating or when it is not?

It's not clear (to me, at least) what "body" you are referring to. In any case, does the moment of inertia of a body change when the body rotates?

 

[jbriggs444]

Is it possible that @Ugnius is thinking about a rod which is initially vertical (like a fence post) with a moment of inertia calculated about a vertical axis? Then having that rod rotate about some other axis (like a fence post tipping over). Then we calculate its moment of inertia about a vertical axis again. And find, unsurprisingly, that the moment of inertia has changed.

 

[Doc Al]

I'm sure that's what's going on, but let's await further clarification.