A system of four particles made of 20 g at (4,0), 30 g at (0,6), 25 g at (-4,3) and 40 g at (-3,2) in the xy-plane, rotate about the z-axis through the centre of the coordinate system. The coordinates are given in units of centimetres. Calculate the moment of inertia of the system.

Question

anonymous · Answer

I calculated this using the formula $$I = \sum_{}^{}Mr ^{2}$$

anonymous · Answer

And got $$2545gcm^{2}$$

anonymous · Answer

Drawing the problem, 25g & 40g lied on the same plane.

anonymous · Answer

Am I on the right path to have summed the whole inertia on all those points?