Physics – 1.5.3 Centre of gravity | e-Consult

Centre of Gravity - Definition:

The centre of gravity (CG) is the point at which the entire weight of an object can be considered to be concentrated. It is the point where the vertical line of gravity (the line of action of the weight of the object) passes through. Essentially, it's the average position of all the mass in the object.

Stability and Centre of Gravity:

The position of the centre of gravity significantly affects the stability of an object. An object is more stable if its centre of gravity is low. This is because a lower CG means that a greater torque (turning force) is required to tip the object over. Conversely, an object with a high centre of gravity is less stable and more likely to topple. Consider a simple example: a wide, flat object is more stable than a narrow, tall object, even if they have the same mass. This is because the wide object has a lower centre of gravity.

The stability of an object is also related to the base of support. A wider base of support raises the centre of gravity, which can reduce stability. Therefore, a combination of a low centre of gravity and a wide base of support provides the greatest stability.