Question

6. Describe how can you experimentally determine the
position of the centre of gravity of an irregular shaped
sheet of cardboard.​

Answer 1

Once the setup becomes steady, mark a line along the thread on the cardboard. Hold the setup by the nail in other holes and draw lines along the plumb line. You will notice that all the lines intersect at the same point. This point is the centre of gravity of the cardboards.

Correct me if I'm wrong.