Four particles each of mass m are kept at the four corners of a square of edge a. Find the moment of inertias of the system about a line perpendicular to the plane of the square and passing through the centre of the square.

Explanation

The perpendicular distance of every particle from the given line is `a// sqrt(2)` . The moment of inertia of one particle is , therefore, `m(a//sqrt(2))^(2) = (1)/(2) ma^(2) ` The moment of inertia of the system is,
therefore, ` 4 xx (1)/(2) ma^(2) = 2 ma^(2)` .