To locate centre of gravity by a balancing method
The centre of gravity of a long thin object such as a ruler or billiard cue may be found approximately by simply balancing it on a straight-edge. The same method could also be used for a thin sheet or lamina of cardboard or metal, except that in this case it is necessary to balance in two positions. Fig. 6.7 shows this method being
used to find the centre of gravity of an artist’s palette. The palette is balanced on the edge of a straight ruler in two directions AB and CD, and the lines of balance are marked with pencil lines. Since the centre of gravity, G, is situated on both lines, it must actually lie at their point of intersection. This may be checked by balancing once more in a third position EF. The edge of the ruler should now pass through the intersection of the two previous lines.