Describe what you see. Now attempt to generate a standing wave on the string. Find the first three harmonics by changing the frequency of the function generator. Verify that the relationship between wavelength, frequency, and tension holds true for the speaker-string system. You can measure the frequency f of the wave using the strobe light.
All systems have one or more natural frequencies of vibration.
These correspond to the frequencies of vibration that require the least amount of energy to maintain. In the case of an air column, the natural frequency depends on its length and the temperature. The air column can be forced into vibration by placing a vibrating tuning fork in its proximity. It will vibrate with the greatest amplitude when the frequency of the tuning fork coincides with one of its natural frequencies. When this occurs, the air column is said to be in resonance with the tuning fork.