Question

A rod of uniform mass 2kg has a length of 5m. What will be its moment of inertia about a line perpendicular to the rod and passing through its middle point?

• A. $25kg-m^2$
• B. $\frac{25}{6}kg-m^2$
• C. $\frac{25}{3}kg-m^2$
• D. $\frac{15}{7}kg-m^2$

Answer 1

The correct option is B $\frac{25}{6}kg-m^2$

As proved and thoroughly explained in the previous video that,
${\left\{\begin{array}{c}M.I\end{array}\right\}}_{rodaboutitscentre}=\frac{M{L}^2}{12}$

Putting all the given values,
$I=\frac{2\times (5{)}^2}{12}=\frac{25}{6}kg-m^2.$