Three point sized bodies each of mass M fixed at three corners of light triangular frame of side length L about an axis perpendicular to the plane of frame and passing through centre of frame the moment of inertia of three bodies is

What is 3mL^2

To find the moment of inertia of the three bodies, we need to know the distribution of the masses within each body. Assuming each body is a point mass and considering the triangular frame as an equilateral triangle, we can calculate the total moment of inertia.

The moment of inertia of a point mass rotating about an axis passing through its center of mass is given by the formula:

I = m * r^2

Where:
I = moment of inertia
m = mass of the body
r = distance of the body from the axis of rotation

Since all three bodies are point-sized and fixed at the corners of the equilateral triangle, the distance of each body from the axis of rotation is L/√3 (dividing the triangle into two right-angled triangles).

The total moment of inertia of all three bodies can be calculated as the sum of the individual moment of inertia for each body:

I_total = I_1 + I_2 + I_3

I_total = (m * (L/√3)^2) + (m * (L/√3)^2) + (m * (L/√3)^2)

Simplifying the equation:

I_total = 3 * m * (L^2/3)

Therefore, the moment of inertia of three bodies fixed at the corners of a triangular frame of side length L is given by:

I_total = m * L^2/3