Question

State the MI of a thin rectangular plate-of mass M, length l and breadth b about its transverse axis passing through its centre. Hence find its MI about a parallel axis through the midpoint of edge of length b.

Answer 1

Consider a thin rectangular plate of mass M, length l and breadth b. The MI of the plate about its transverse axis passing through its centre is

I_CM = M(l² + b²)

For a parallel axis through the midpoint of its breadth, h = \(\frac12 l\). Therefore, by the theorem of parallel axis, the MI about this axis is