Forced Oscillations and Resonance LO (j)
When a system performs oscillations without any applied force, the frequency of the oscillation is a characteristic of the system and is called the natural frequency, fo .
Oscillations in which a periodic force is imposed are called forced resonance. Systems will then vibrate at the frequency of the periodic force, f.
Examples include the
1) Vibrations of a pendulum clock.
2) Vibrations of a tuning fork when exposed to the periodic force of a sound wave.
3) Vibration of a bridge under the influence of marching soldiers or periodic wind.