# Definition of Parallel-axis theorem

What is the physical meaning of each term in the parallel-axis theorem?

I=I com +Mh^2

## Answers and Replies

Doc Al
Mentor
What is the physical meaning of each term in the parallel-axis theorem?

I=I com +Mh^2
Not sure what you mean by 'physical' meaning, but:
I = moment of inertia about some axis a distance 'h' from the center of mass
Icom = moment of inertia about some axis (parallel to the other) passing through the center of mass
M = mass of object
h = distance between those two parallel axes

You can think of it as the sum of the moment of inertia about the center of mass and the moment of inertia of the total mass (considered as a point mass) about the axis in question.

Andrew Mason
Science Advisor
Homework Helper
What is the physical meaning of each term in the parallel-axis theorem?

I=I com +Mh^2
Icom is the moment of inertia of an object about an axis through the centre of mass. I is the moment of inertia of the object about an axis that is parallel to the axis through the centre of mass (com) and separated from it by a distance h. M is the mass of the object.

AM

Thanks, that helped a lot!