Question

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 $\frac{x}{7}$ The the value of $x$ is ___

Answer 1

The correct answer is 5.

I1​=52​m1​R2+m1​R2
I1​=m1​R2(57​)
I1​=7R2

I2​=4m2​R2​+m2​R2
I2​=45​m2​R2
I2​=5R2
I1​I2​​=75​
x=5