SHM Chapter 23 x vs f resonance

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, f_o .

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.