Question

Three-point masses each of mass $m$ are placed at the corners of an equilateral triangle of side $l$.The moment of inertia of the system about an axis coinciding with one side of the triangle is

• A. $3m{l}^2$
• B. $m{l}^2$
• C. $\frac{3}{4}m{l}^2$
• D. $\frac{2}{3}m{l}^2$

Answer 1

The correct option is C $\frac{3}{4}m{l}^2$

$Z=m{r}^2$

$=m{\left(\frac{\sqrt{3}}{2}b\right)}^2$

$=\frac{3m{b}^2}{4}$

$\therefore Z=\frac{3m{b}^2}{4}$

$Answer=c$