The radius of gyration of a body about an axis at a distance of `12cm` from its centre of mass is `13cm`. Find its radius of gyration about a parallel axis through its centre of mass.

Explanation

By parallel axes theorem
`M (13)^(2) = I_(0)+M(12)^(2)`
` I_(0) = M (13^(2) - 12 ^(2)) = M ( 25)`
Its radius of gyration about a parallel axes through its centre of mass
` k = sqrt(I_(0)/M) = sqrt(25) = 5 cm `