Question

The radius of gyration of a body about an axis at a distance of $6\, cm$ from its centre of mass is $10\, cm$. Then, its radius of gyration about a parallel axis through its centre of mass will be

• A. 800 cm
• B. 8 cm
• C. 0.8 cm
• D. 80 m

Answer 1

Answer: (B)

$T_{A B}=I_{ CM }+M h^{2}$
$M K_{AB}^{2}=M K_{ CM }^{2}+M h^{2}$
$K_{A B}^{2}=K_{ CM }^{2}+h^{2}$
Given, $K_{A B}=10\, cm,\, h=6\, cm$
Putting them, we get
$K_{ CM }=8\, cm$