The radius of gyration of a body about an axis at a distance of 12 cm from its centre of mass is 13 cm. 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 axis through its centre of mass
`K=sqrt((I_(0))/(M))=sqrt25=5cm`