Four point masses, each of value m, are placed at the corners of a square ABCD of side 1. The moment of inertia of this system about an axis through A and parallel to BD is

Four point masses, each of value m, are placed at the corners of a squ

1.	Four point masses, each of value m, are placed at the corners of a square ABCD of side 1. The moment of inertia of this system about an axis through A and parallel to BD is
Answer» `ml^2` `2ml^2` `sqrt3 ml^2` `3ml^2` Solution :`AO = cos 45^(@) = (l)/(2)` `THEREFORE AO xx (1)/(sqrt2)= (l)/(2)` or `AO = (l)/(sqrt2)` `I = I_(D) + I_(B) + I_(C)` or `I = (2ml^2)/(2) + m ((2L)/(sqrt2))^(2)` = `(2ml^(2))/(2) + (4ml^2)/(2)` or `I = (6ml^2)/(2) = 3ml^2`