Side of an equilateral triangle is I . Three point masses, each of magnitude m, are palced at the three vertices of the triangle . Momment of inertia of this system about one side of the triangle as axis is given by

Options

A. `(3ml^2)/4`
B. `4/3 mt^2`
C. `3/2 ml^2`
D. `2/3 ml^2`

Answer

A

Explanation

Distance of corner mass from opposite side = r
`r^(2) = l^(2) - ((l)/(2))^(2) = (3l^(2))/(4)`
`l = mr^(2) = (3)/(4) ml^(2)`