Question

Radius of gyration of the system of two rods each of mass ' $m^{\prime }$ and length $l^{\prime }$ about an axis shown is:

• A. $l\sqrt{\frac{1}{72}}$
• B. $l\sqrt{7}$
• C. $l\sqrt{\frac{7}{72}}$
• D. None

Answer 1

The correct option is C $l\sqrt{\frac{7}{72}}$

$\begin{array}{c}2m{K}^2=\frac{m{l}^2}{12}+\frac{m{l}^2}{12}+\frac{m{l}^2}{36}\\ K=l\sqrt{\frac{7}{72}}\\ Ans.\left(C\right)\end{array}$