What experiments demonstrate the centre of gravity?

The Balancing Spoon and Fork experiment and the Plumb Line experiment are two demonstrations of the centre of gravity.

The Balancing Spoon and Fork experiment is a simple yet effective way to demonstrate the concept of the centre of gravity. In this experiment, a spoon and a fork are interlocked and balanced on the edge of a glass using a toothpick. Despite the weight of the spoon and fork, they remain balanced because the centre of gravity of the combined system (spoon, fork, and toothpick) is directly below the point where the toothpick touches the glass. This experiment shows that an object will remain in equilibrium as long as its centre of gravity is supported.

The Plumb Line experiment is another practical demonstration of the centre of gravity. A plumb line is a string with a weight at one end that, when suspended, will hang vertically due to gravity. If you suspend an irregularly shaped object, like a cardboard cut-out, from a point and let it swing until it comes to rest, the plumb line will pass through the object's centre of gravity. By repeating this from different suspension points and marking where the plumb line crosses, the intersection of these lines will indicate the centre of gravity. This experiment demonstrates that the centre of gravity is the point where all of the weight of an object appears to be concentrated.

Both of these experiments provide a visual and practical understanding of the centre of gravity, a fundamental concept in physics. They show that the centre of gravity can be located in the space occupied by the object (like in the spoon and fork experiment) or outside it (as in some irregularly shaped objects in the plumb line experiment).