Is I=Mk^2 the Same as I=mr^2 in Physics Nomenclature?

[SadPanda6022]

Hey guys, quick question.

I got confused in some nomenclature between some books and wanted to clarify somehow. A book I have has I=Mk^2 as defining a radius of gyration. Is this the same as I-mr^2?

Terminology was just confusing me.Thanks guys.

 

[SadPanda6022]

Oops, I meant I=mr^2.

apologies

 

[haruspex]

A book I have has I=Mk^2 as defining a radius of gyration. Is this the same as I=mr^2?

It depends what r is supposed to be. Certainly
"I=Mk², where M is mass, k is the radius of gyration and I is the moment of inertia about the mass centre"
is exactly the same as
"I=mr², where m is mass, r is the radius of gyration and I is the moment of inertia about the mass centre".
But most writers reserve r to be a directly observable radius, such as the radius of a hoop or of a point mass in a circular orbit.