inertial mass


noun Physics.

the mass of a body as determined by the second law of motion from the acceleration of the body when it is subjected to a force that is not due to gravity.
the measure of the property of inertia. Compare Eötvös experiment, inertia(def 2a), gravitational mass.

British Dictionary definitions for inertial mass

inertial mass

noun

the mass of a body as determined by its momentum, as opposed to gravitational mass. The acceleration of a falling body is inversely proportional to its inertial mass but directly proportional to its gravitational mass: as all falling bodies have the same constant acceleration the two types of mass must be equal