turning effects of forces

definition of moment/ turning effect of force

the moment of a force is the product of the applied force and the perpendicular distance between the pivot and the line of action of the applied force
moment (Nm) = applied force x perpendicular distance

definition for centre of gravity

the centre of gravity of an object is defined as the point through which its weight appears to act through

principle of moments

when an object is in equilibrium, the sum of clockwise moments is equal to the sum of anticlockwise moments about the same pivot/ any axis

stability; type of equilibrium

to increase the stability of an object:
base area of object should be as large as possible
centre of gravity of the object should be as low as possible

types of equilibrium: stable

when the object is tilted slightly, the centre of gravity rises but falls to its original position due to the moment produced by its weight (anticlockwise) about the pivot

types of equilibrium: unstable

when the object is tilted slightly, the centre of gravity falls and the object topples due the moment produced by its weight (clockwise) about the pivot

types of equilibrium: neutral

when the cone is displaced horizontally, the centre of gravity remains at the same height