The radius of gyration of a body about an axis at a distance of 4 cm from the centre of gravity is 5 cm. Its radius of gyration about a parallel axis through centre of gravity is

Options

A. `sqrt(31)cm`
B. 1 cm
C. 3 cm
D. none

Answer

C

Explanation

`K_(0)^(2)=K_(c )^(2)+h^(2)`
`K_(c )^(2)= K_(0)^(2)-h^(2)=25-16`
`K_(c )^(2)=9`
`K_(c ) = 3 cm`.