rest mass

American  

noun

Physics.

1. the mass of a body as measured when the body is at rest relative to an observer, an inherent property of the body.

---

rest mass British  

noun

1. the mass of an object that is at rest relative to an observer. It is the mass used in Newtonian mechanics

---

rest mass Scientific  

1. In Special and General Relativity, the observed mass of a body that is not in motion with respect to the observer.

2. Also called invariant mass

3. Compare relativistic mass

---

Etymology

Origin of rest mass

First recorded in 1910–15

Example Sentences

See Examples For:

rest mass

Consequently, its accretion disk glows brightly, radiating away about a tenth of its rest mass and exceeding by orders of magnitude the total luminosity from stars in its host galaxy.

From Scientific American ● Jan. 31, 2021

Nuclear processes could not account for their energy output, because they release only a percent fraction of their rest mass as pure energy.

From BBC ● Jan. 26, 2016

We can determine the BE of a nucleus from its rest mass.

From Textbooks ● Aug. 12, 2015

The pieces are at rest when separated, and so the energy put into them increases their total rest mass compared with what it was when they were glued together as a nucleus.

From Textbooks ● Aug. 12, 2015

Thus, for example, in a body at rest mass is patent, energy latent and potentiality of conscious manifestation sublatent.

From A History of Indian Philosophy, Volume 1 by Dasgupta, Surendranath