Question

Three rods each of length l and mass m are placed along the x, y and z axes in such a way that one end of each of the rod is at the origin. The moment of inertia of this system about z axis will be

Answer 1

MOI of rod about an axis perpendicular to the rod and passing through edge of the rod = (ML^2)/3

And MOI about an axis along its axis = 0

MOI about z-axis of the system = 0 + (ML^2)/3 + (ML^2)/3

= (2ML^2)/3 ..... answer.....

Answer 2

$\frac{2m {l}^{2} }{3}$

its your answer..........