# Turning a Straight Wire into a wheel with spokes, solve for I

1. Oct 11, 2007

### gkinnish

1. The problem statement, all variables and given/known data
A stiff uniform wire of mass M_0 and length L_0 is cut, bent, and the parts soldered together so that it forms a circular wheel having four identical spokes coming out from the center. None of the wire is wasted, and you can neglect the mass of the solder.

2. Oct 11, 2007

### learningphysics

Can you show your work?

3. Oct 18, 2007

### gkinnish

solving for the moment of inertia i came up with 4/3(M/(L/(2pi+4))^2)

4. Oct 18, 2007

### learningphysics

can you show your steps... that's not what I'm getting... some things are similar... some things are different.

The mass of each spoke is $$\frac{1}{2\pi + 4}*M_0$$

The length of each spoke is $$\frac{1}{2\pi + 4}*L_0$$

What's the moment of inertia of each spoke?

What's the mass of the circular section? What's the moment of inertia of the circular section?