- #1

drj1

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## Homework Statement

Figure (a) shows a disk that can rotate about an axis at a radial distance h from the center of the disk. Figure (b) gives the rotational inertia I of the disk about the axis as a function of that distance h, from the center out to the edge of the disk. The scale on the I axis is set by IA = 0.010 kg·m2 and IB = 0.210 kg·m2. What is the mass of the disk?

Here's a link to the image --> http://www.webassign.net/hrw/10-35.gif

## Homework Equations

Inertia=Icom + Mh^2

=(mL^2)/2 + Mh^2

## The Attempt at a Solution

I set .010= (mL^2)/2 and solved for L^2 which turns out to be (.02/m). I then plugged this term into L^2 variable of the equation I=(mL^2)/2 + Mh^2. Then I plugged in .210 for I and .2 for h and solved for m which came out to be about 5.25. I thought I had it right but I don't. Help would be great I appreciate it.