Moments and stability

Moment of a force

turning effect produced when force(s) cause an object to turn or rotate about a pivot

Pivot (fulcrum)

The point about which moments act in a clockwise or anticlockwise direction

The equation linking moment of a force, force and distance

M = Fd

M

The symbol for moment of a force

F

The symbol for force

d

The symbol for distance

Unit for moment of a force

Newton-metre (Nm)

Unit for force

Newtons (N)

Unit for distance

Metres (m)

Principle of moments

When the total clockwise moments about a pivot is equal to the total anticlockwise moments in equilibrium

Centre of gravity

The point at which the entire weight of an object can be considered to act

Stable

object is able to resist tipping over due to the line of action of the centre of gravity falling within its base