Review article
Weight and Gravity - Problems with Meanings and Definitions
Vjera Lopac
; Faculty of Chemical Engineering and Technology, University of Zagreb, Croatia
Abstract
Physicists, philosophers and researchers in physics education do not agree on the precise meaning and definition of the term weight. Most physicists advocate the theoretical (conceptual) definition, according to which weight is product of mass and the local acceleration of free fall, in line with the definition of weight in the international standard ISO 800004. It takes into account both the position of the observer and the inertial forces in accelerated reference systems. On the Earth’s surface weight is defined as the product of mass and combined gravitational and centrifugal acceleration. The same definition explains the concept of weightlessness of a body freely falling or moving in an orbit. Some authors advocate the operational definition of weight according to which weight is defined as the result of measurement using the spring balance. The article analyzes the approach to the weight in physics courses and emphasizes the need to replace the operational definition by the internationally agreed definition of weight.
Keywords
weight; gravity; theoretical definition; operational definition; weightlessness; noninertial reference system; inertial forces; local acceleration of free fall; load force
Hrčak ID:
103734
URI
Publication date:
10.4.2013.
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