|
Vibration refers to mechanical motion. The motion may be: Vibration is occasionally desirable. For example the motion of a tuning fork, the reed in a woodwind instrument or harmonica, or the cone of a loudspeaker is desirable vibration, necessary for the correct functioning of the various devices. The vibrating alert in a cell phone or the much larger vibrations of a vibratory compactor are additional examples where the vibration is desired. More often, vibration is undesirable, wasting energy and creating unwanted sound. For example, the motions of engines, electric motors, or any mechanical device in operation are usually unwanted vibrations. Such vibrations can be caused by imbalances in the rotating parts, uneven friction, the meshing of gear teeth, parts that are dragging together, etc. Careful designs usually minimize unwanted vibrations or add dampers to suppress their transmission outside of the point of generation. Vibrations produce music, which is sound. Sound produces vibrations in materials because sound consists of pressure waves in air (or other materials). The pressure in the waves "pushes" on objects (as you would expect pressure to do), but being a wave, it is changing rapidly, pushing harder and softer repeatedly many times a second. This pushing causes the material subjected to the sound to vibrate.
See also | ||||||||
|
| |||||||||
 |
|
| |