relativistic mass


noun Physics.

the mass of a body in motion relative to the observer: it is equal to the rest mass multiplied by a factor that is greater than 1 and that increases as the magnitude of the velocity increases.

Scientific definitions for relativistic mass

relativistic mass
[ rĕl′ə-tə-vĭstĭk ]

In Special and General Relativity, the observed mass of an object moving with respect to the observer. The relativistic mass is a function of the rest mass and the velocity of the object. Compare rest mass.