Weight
. Weight, measure of the gravitational force exerted on an object (see Gravitation ). The weight of an object may be determined by using either a comparative method, as with a chemical-laboratory balance, or by measuring the gravitational force directly by means of a spring scale, such as the familiar bathroom scale (see Mass ). The deflection of a spring scale depends on the local gravitational attraction; therefore, a spring scale would record different weights for the same mass (amount of matter) at locations with a different gravitational attraction. One kilogram of mass, for example, might weigh 2.2 lb at sea level at latitude 45° North, but slightly less on the top of a high mountain or at the equator, although the mass remains unchanged. More dramatically, an object with 1 kg of mass might weigh 2.2 lb on earth but only 0.35 lb on the moon. This problem is avoided by using the so-called beam scale such as that employed in the chemical-laboratory balance. In this, two pans are su...