Weight and mass

In avant-garde accurate usage, weight and accumulation are fundamentally altered quantities: accumulation is an built-in acreage of matter, admitting weight is a force that after-effects from the activity of force on matter: it measures how acerb the force of force pulls on that matter. However, in best applied accustomed situations the chat "weight" is acclimated when, strictly, "mass" is meant.416 For example, best bodies would say that an article "weighs one kilogram", alike admitting the kilogram is a assemblage of mass.

The accurate acumen amid accumulation and weight is unimportant for abounding applied purposes because the backbone of force is about the aforementioned everywhere on the apparent of the Earth. In a compatible gravitational field, the gravitational force exerted on an article (its weight) is anon proportional to its mass. For example, article A weighs 10 times as abundant as article B, so accordingly the accumulation of article A is 10 times greater than that of article B. This agency that an object's accumulation can be abstinent alongside by its weight, and so, for accustomed purposes, belief (using a belief scale) is an absolutely adequate way of barometer mass. Similarly, a antithesis measures accumulation alongside by comparing the weight of the abstinent annual to that of an object(s) of accepted mass. Since the abstinent annual and the allegory accumulation are in around the aforementioned location, so experiencing the aforementioned gravitational field, the aftereffect of capricious force does not affect the allegory or the consistent measurement.

The Earth's gravitational acreage is not compatible but can adapt by as abundant as 0.5%17 at altered locations on Earth (see Earth's gravity). These variations adapt the accord amid weight and mass, and charge be taken into annual in aerial attention weight abstracts that are advised to alongside admeasurement mass. Spring scales, which admeasurement bounded weight, charge be calibrated at the area at which the altar will be acclimated to appearance this accepted weight, to be acknowledged for commerce.citation needed

This table shows the aberration of dispatch due to force (and appropriately the aberration of weight) at assorted locations on the Earth's surface.1