rest mass


Definition of rest mass

: the mass of a body exclusive of additional mass the body acquires by its motion according to the theory of relativity

Examples of rest mass in a Sentence

Recent Examples on the Web The Higgs symmetry was restored early on, and so none of the Standard Model particles possessed a rest mass prior to that time. Ethan Siegel, Forbes, 21 Apr. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'rest mass.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of rest mass

1914, in the meaning defined above

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The first known use of rest mass was in 1914

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Last Updated

30 Apr 2021

Cite this Entry

“Rest mass.” Dictionary, Merriam-Webster, Accessed 18 Jun. 2021.

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