Statics is the action of one body on another. A force is either a push or a pull. A force tends to move a body in the direction of its action. The action of a force is characterized by its magnitude, by the direction of its action, and by its point of application. Thus, force is a vector quantity, because its effect depends on the direction as well as on the magnitude of the action. Forces are classified as either contact or body forces. A contact force is produced by direct physical contact; an example is the force exerted on a
Quantity and time, mass and force, temperature, energy, and quanta. A distinction has also been made between intensive quantity and extensive quantity as two types of quantitative property, state or relation. The magnitude of an "intensive quantity" does not depend on the size, or extent, of the object or system of which the quantity is a property, whereas magnitudes of an "extensive quantity" are additive for parts of an entity or subsystems. Thus, magnitude does depend on the extent of the entity or system in the case of extensive quantity. Examples of intensive quantities are density and pressure, while examples of