Times must be hard when an Oxford Physics student asks an internet forum of mainly sixth-formers for help on mechanics...
i know what it is .....i just havent grasped the concept and what it is
Obviously, given the expression for reduced mass, the greater the difference in mass between the atoms, the more accurate using the reduced mass will be.
That's not written very well but I'm in a rush.
Do you mean the concept of mass as opposed to weight...