Question

3.
A metallic ring of mass 1kg has moment of inertia 8 kgm2
, when rotating about one of its diameters.
It is molten and remoulded into a thin uniform disc
of same radius. How much will its M. I be when
rotated about its own axis.​

Answer 1

moment of inertia of ring about it's diameter is 1/2MR²

8=1/2(1*R²)

16=R²

R=4

if remolted to-dos of same radius mjass of disk remain same

MI=1/2MR²

MI=1/2(1*4²)

M.I=8kgm²