The radius of gyration of a solid sphere of radius r about a certain axis is r. The distance of this axis from the centre of the sphere is

Options

A. r
B. 0.5 r
C. `sqrt(0.6) r`
D. `sqrt(0.4) r`

Answer

C

Explanation

`I = mk^(2) = mr^(2) = I_(CM) + mh^(2) = (2)/(5) mr^(2) + mh^(2)` or `h^(2) = (3)/(5) r^(2) or h = sqrt(0.6)` r