forced oscillation การใช้

That is supported by ability to transfer energy of forced oscillations from one resonator to the other resonator.
If the wave vector and frequency of the forced oscillation at the difference frequency of the two signals satisfies the dispersion relation for electrostatic waves, such waves would exist and begin to propagate.
The interference of the stock with the barrel's forced oscillation as the bullet passes down the bore can cause the barrel to vibrate inconsistently from shot to shot, depending on the external forces acting upon the stock at the time of the shot.