- Resonance is the natural vibrational frequency of a system. Stimulation at that frequency produces energy transfer without much loss. In the simplest cases, resonance frequencies are the frequencies that produces standing waves.
- e.g., a swingset (pendulum) – kick your legs at a particular frequency to maximize the energy transfer; pipe organ; breaking a wine glass by singing
- If you continue to add energy at the resonant frequency, the wave oscillations will grow quickly
Resonance of a musical instrument
- Guitar strings play a certain note when you pluck them (1st harmonic or fundamental mixed with additional harmonics)
- You can change that note by altering the length of the string (i.e., the wavelength of the first harmonic – which also changes the frequency)
- You can also change the note by using a different thickness of string (i.e., the velocity of the wave in that medium will be different – and therefore the frequency)