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<record version="1" id="143">
 <title>inertia tensor</title>
 <name>InertiaTensor</name>
 <created>2006-03-28 00:25:45</created>
 <modified>2006-03-28 00:25:45</modified>
 <type>Definition</type>
 <creator id="1" name="bloftin"/>
 <modifier id="1" name="bloftin"/>
 <author id="1" name="bloftin"/>
 <classification>
	<category scheme="msc" code="45.40.-f"/>
 </classification>
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 <content>The inertia tensor is straight forward to calculate in theory from equation (1).  However, in practice finding the inertia tensor of an object is quite involved and high precision is needed in applications such as spacecraft design.

$$ \sum_i = m_i $$

$$ I =
\left[ \begin{array}{ccc}
{\sum_i {m_i (r^2_i - x^2_i)}} &amp; -\sum_i m_i x_i y_i &amp; -\sum_i m_i x_i z_i \\
-\sum_i m_i y_i x_i &amp; \sum_i m_i (r^2_i - y^2_i) &amp; -\sum_i m_i y_i z_i\\
-\sum_i &amp; -\sum_i &amp; \sum_i \end{array} \right] $$</content>
</record>
