The moment of inertia of solid sphere about its diameter
IS=32MR2 The moment of inertia of a thin walled hollow sphere about its diameter is
IH=52M(R23−R13)(R25−R15) where
R1andR2 are its internal and external radii
=
IH>Is The reason is that in solid sphere the whole mass is uniformly and continuously distributed about its center in the whole volume while in hollow sphere the mass is distributed on the surface of sphere