Inertia, and/or mass is the ratio of the net force [f] exerted on and/or by
an object; body, or mass of material substance to the time rate of change in
the motion [s/t²] that it causes: That is mass and/or inertia are constants;
so that at any given (instant) point in time the ratios w/g, and 2ft²/s are
equal constants!

Impetus, and/or momentum is the product of the magnitude of the mass [m] and
the magnitude of the speed [v] - which speed is relative to the speed of the
observers, and/or the ground - where the magnitude of the impulse and/or
impact that can be exerted is the product of the magnitude of the thrust [f]
exerted and its duration [t].

Impetus is added to a mass by accelerating it, and lost by decelerating it:
Like throwing stones.

Nope ,,intera is the energy sum it displaces.
The energy exchange is not the energy mass dislaces but all the energy
mass contains is the energy it displaces.
Per time unit wile bouyant in energy mass displaces more energy per
time unit in motion.
As the univese expands condenced energy dont. Yet C and the pressure
of energy is constant because energy dont have a shape but rather a time
unit of space reacts with space at C.