reduced mass
"effective" inertial mass appearing in the two-body problem of Newtonian mechanics; quantity which allows the two-body problem to be solved as if it were a one-body problem
en-GB/ɹɪˈdjuːst ˈmæs/
en-US/ɹɪˈdust ˈmæs/
"effective" inertial mass appearing in the two-body problem of Newtonian mechanics; quantity which allows the two-body problem to be solved as if it were a one-body problem