Moment

Moment of Force

When a force is acted on a body, it results in either displacement of the body or its rotation about a point or axis. This rotation or turning effect of force may be clockwise or anticlockwise.

The turning effect of the force acting on a body about an axis is called the moment of the force.

The moment of the force is equal to the product of the magnitude of the force and the perpendicular distance of the line of action of the force from the axis of rotation or fulcrum.

Mathematically,

Moment = F × S

Here, F= force applied

S= perpendicular distance of the line of action of the force from the fulcrum

The SI unit of a moment is Nm but Ncm is also in use. If the force is not applied perpendicular on a lever, the value of moment decreases.

Law of moment

The law of moment states that “In the equilibrium condition of the lever, the sum of the anticlockwise moment is equal to the sum of the clockwise moment”

Effort × Effort distance = Load × Load distanceMathematically,

(Anticlockwise) (Clockwise)