Mass, gravitational weight and apparent weight
Mass is in kilograms; gravitational weight is a force.
Key knowledge
In a Newtonian gravitational field g, gravitational weight is W=mg. Mass and weight are different quantities: changing the local field changes weight without changing the body’s mass. A supporting scale measures a contact force, often called apparent weight; in free fall that support can vanish while gravity remains present.
Values and equations
W=mg
- W
- Vector gravitational weight N
- m
- Mass kg
- g
- Local gravitational acceleration vector m s⁻²
Conditions and scope
- Use the explicitly stated gravitational-weight convention; weight terminology can differ in applied contexts.
- A scale’s support force equals mg only under the corresponding force-balance conditions, such as rest with no other vertical forces in the local inertial approximation.
Sources · 2
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Samuel J. Ling, Jeff Sanny and William Moebs — OpenStax, Rice University, University Physics (2016)2 sources
- University Physics Volume 1, §5.4: mass and weightSamuel J. Ling, Jeff Sanny and William Moebs — OpenStax, Rice University, University Physics (2016)Textbook chapter
- University Physics Volume 1, §5.6: common forcesSamuel J. Ling, Jeff Sanny and William Moebs — OpenStax, Rice University, University Physics (2016)Textbook chapter
Evidence and review
Read §5.4 Weight and Gravitational Force, free fall/weightlessness and §5.6 normal-force examples. No universal Earth g or statement that free fall eliminates the gravitational interaction.
2026-10-10 · /root/audit_life_earth_chemistry — independent Chemistry/Life/Earth editor. Independent AI editorial review of this entry's statements, equations, applicability conditions and source coverage. Source checks apply to these claims within their stated limits.
Entry details
Permanent link to this entry ↗- Record identity
- foundation-physics-mass-weight
- Revision
- foundations-refresh.1
- Structured reference record
- Foundational reference additions