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Three balls of masses 2 kg, 4 kg and 6 kg respectively are arranged at centre of the edges of an equilateral triangle of side 2 m. The moment of inertia of the system about an axis through the centroid and perpendicular to the plane of triangle, will be kg m2.
4
[figure]
each mid-point is at the inradius from the centroid G: r = a2 3 = 22 3 = 1 3 m
I = (2 + 4 + 6)r2 = 12 13 = 4 kg m2
Answer: 4
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