Question

it's urgent plzzz answer this.

two circular discs A and B of same mass and same thickness are made of two different metals whose densities are da and db(da>db). their moments of inertia about the axis passing through their center of gravity and perpendicular to their planes are Ia and Ib. which is greater Ia or Ib

Answer 1

Moment of inertia of a thin disk isI=12MR2now if MA=MBthen AA×ρA=AB×ρBas thickenss is same for both of themnow if ρA>ρB then AB>AAso RB>RA where R is teh radius.so IB>IA