A circular disc of radius R and thickness (R/6) has moment of inertia I about an axis passing through its centre and perpendicular to its plane. It is melted and recast into a solid sphere. The moment of inertia of the sphere about its diameter on axis of rotation is

Question

Infinity Learn · Accepted Answer

When the disc is melted and recasted into a solid sphere, then,Volume of disc $$=$$ Volume of the sphere$$π$$$$R2$$×(R/6)=(4/3)π$$r3$$∴$$r=R/2Now$$, $$I=MR22$$ (Fordisc) I′$$=25MR2$$ (For$$ $$sphere) ∴ I′$$=25M$$×$$R22=12MR2$$×$$15or$$ , I′$$=I/5$$

A circular disc of radius R and thickness (R/6) has moment of inertia I about an axis passing through its centre and perpendicular to its plane. It is melted and recast into a solid sphere. The moment of inertia of the sphere about its diameter on axis of rotation is

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material