# Homework Help: Inertia and magnetic moment

1. Apr 8, 2014

### besnik93

1. The problem statement, all variables and given/known data
For any flat object, located in the x-y plan applies to the equation:
Ix+Iy=Iz

where Ix,Iy,Iz is the moments of inertia about the x-axis, y-axis and z-axis.
A flat circular coil has n windings and radius r. The mass of the coil is m. The coil is located in the x-y plan centered on (0,0). The coil moment of inertia about the z-axis is called Iz

a) Give a formula of Iz. Also specify a formula for Ix and Iy.

The coil has one turn. The current in the coil is I.
b) Give the magnetic moment μ of the coil.

3. The attempt at a solution

a+b) I am thinking of using the definition of the magnetic moment of a current loop, but i cant get further, can someone help please?

2. Apr 9, 2014

### paisiello2

Kind of a strange question since it asks two completely different questions:

a) Do you know formula for the mass moment of inertia for a ring?

b) Yes, simply use the definition for a magnetic moment of a coil.

3. Apr 9, 2014

### besnik93

[
a) Do you know formula for the mass moment of inertia for a ring?

Is it K= rootof(Ic/m)?

4. Apr 9, 2014

### paisiello2

No, it's Iz we're after.