Question

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.

Answer 1

@wio, pls take a look

Answer 2

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

Answer 3

Got 2545gcm^2

Answer 4

What is the issue?

Answer 5

25g and 40g both lie on the same plane. Does that say something?

Answer 6

don't t hey all lie in the same plane?