What is Weight?
{{wiktionary}} The '''weight''' of an object (or the weight of an amount of [[matter]]) is the measure of the intensity of the [[Force (physics)|force]] imposed on this object by the local [[Gravitation| gravitational field]]. Weight should not be confused with the related but quite different concept of [[mass]]. For small objects on Earth, the weight force is directed towards the center of the planet. For larger objects, such as the [[Moon]] orbiting around the Earth, the force is directed towards the [[center of mass]] of the combined system. In common language, the weight of something is typically understood to be the value measured at or near the [[Earth]]'s surface. Unfortunately the common terms used to describe the weight of an object are units of mass such as [[kilogram]]s (kg) or [[Pound (mass)|pounds]] (lbs). For almost all of human history, weight has been measured on the surface of the Earth. Here, the weight is proportional to the mass. Objects which have the same mass have the same weight. An object with the twice the mass of another will also have twice the weight. As a consequence it is common practice to use the two words, mass and weight, as if they mean the same thing and to use kilograms and pounds as the units for both mass and weight. Using the same terms to describe and measure the two different properties has led to confusion between these two properties, mass and weight. Mass and weight are not the same thing. == Units of weight == The unit of weight in the [[International System of Units]] is the [[Newton (unit)|newton]], which is represented by the symbol 'N'. Other units have been in use in the past but have been abandoned, such as the dyne (the unit of force in the old CGS system) or the kilogram-force, which is the force exerted on a kilogram of matter by a 'standard' Earth: a body with a mass of 1&nbsp;kg has a weight of about 9.81 N at [[sea level]]. == Measuring weight == The weight of an object, or of an amount of matter, is typically measured with an instrument such as a [[