posted by Alex .
A uniform rectangular bar with cross-section 66 mm x 54 mm and of length 1.7 m has mass 16kg. It pivots about an axis prependicular to the wider face. The axis is equidistant from the edges and 170 mm from one end. What is the relevant second moment of mass?
The "wider face" is the pair of 66 mm x 1.7 m parallel faces.
First, get the moment of inertia about an axis passing through the centroid of that face. Call it Icm.
Then, use the parallel axis theorem, which is explained at
For the moment of inertia about an axis through the center of mass, see the "cuboid" formula at