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      <title>Moments of Inertia</title>
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      <div class="title_topic3" id="xps10_pagetitle">Moments of Inertia</div>
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      <p class="para_topic">The system calculates the moments of inertia for area using curves, or second moments, of</p>
      <p align="center"><img align="bottom" src="graphics/ana_infoat52.gif"></p>
      <p class="para_topic">where:</p>
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               <p class="para_td">I</p>
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               <p class="para_td">The required moment of inertia</p>
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               <p class="para_td">r</p>
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               <p class="para_td">The distance between the specified axis and the centroid of the area</p>
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               <p class="para_td">A</p>
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               <p class="para_td">The area</p>
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      </table><br><p class="para_topic">The quantity I may be expressed as inches4 or millimeters4. The moment of inertia is resistance to angular acceleration in the same way that mass is resistance to linear acceleration. The system calculates moments of inertia about the XC, YC axes and the centroidal axes. The centroidal axes are the axes through the center of mass and parallel to the XC, YC axes.</p>
      <p class="para_topic">For a figure lying in the XC-YC plane, the moment of inertia about the ZC axis is known as the polar moment of inertia. This is calculated by the formula</p>
      <p align="center"><img align="bottom" src="graphics/ana_infoat51.gif"></p>
      <p class="para_topic">where:</p>
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               <p class="para_td">I</p>
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               <p class="para_td">The required polar moment of inertia</p>
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               <p class="para_td">r</p>
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               <p class="para_td">The distance from the ZC axis</p>
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               <p class="para_td">A</p>
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               <p class="para_td">The area</p>
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