- The mass of a body when at rest.More example sentences
- The concept of the rest mass derives from special relativity.
- The neutrino was known from the start to be an extraordinarily light particle, perhaps massless, since its rest mass could never be detected.
- Any object with a non-zero rest mass (like a dust mote) can never reach light speed.
More definitions of rest massDefinition of rest mass in:
- The British & World English dictionary