Centre of Gravity: Finding the Balance Point of Irregular Objects

We use a plumb line and hook to find the centre of gravity of an irregularly shaped piece of card. A hole is punched in the card and it is suspended from the hook. A plumb line is used to let us draw the vertical line under the hole on which the centre of gravity lies. A second hole is made and a second line is drawn. The centre of gravity is where the two lines cross. Physics - Forces - Learning Points. All objects with mass have a centre of gravity - the point where we can imagine that the mass of the object is concentrated. Simple shapes like squares often have an obvious centre of gravity, whereas irregular shapes often have a centre of gravity that is not so obvious. A Twig Experiment Film. Let students experience real experiments in lab conditions anywhere, from setup, method all the way through to analysis and real-world application.