Q.

If a solid sphere of mass 5 kg and a disc of mass 4 kg have the same radius, then the ratio of moment of inertia of the disc about a tangent in its plane to the moment of inertia of the sphere about its tangent will be x7. The value of x is __________ .             [2023]


Ans.

(5)

I1=25m1R2+m1R2=m1R2(75)

I1=7R2

I2=m2R24+m2R2=54m2R2

I2=5R2

I2I1=57x=5