Question #e35ee

1 Answer
Apr 23, 2014

The moment of inertia is calculated from the sum

I=m1×r21+m2×r22+m3×r23

where ri is the distance of point mass i from the center of mass of the three points. The square of each distance is calculated in Cartesian coordinates as

r2i=(xixcm)2+(yiycm)2

The center-of-mass coordinates (xcm,ycm) can be found from the simple formula below if you know the masses of the three points and their coordinates in any (x,y) plane.

xcm=m1×x1+m2×x2+m3×x3m1+m2+m3

ycm=m1×y1+m2×y2+m3×y3m1+m2+m3