CMD 276 Lecture Notes - Lecture 3: Sound Pressure, Sound, Fundamental Frequency
18 Feb 2017
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Document Summary
Amount of motion of a vibrating object or amount of pressure change generated by the object. Distance molecules move away from rest point when displaced. Measurement of pressure changes that occur in the air as a result of displaced molecules. Amount of energy expended in a second measured over a particular area. Energy - capacity of an individual or object to perform work. Work - push or pull that moves an object. 1 erg = amount of work done when a force of 1 dyne moves an object 1 cm. Power - amount of energy expended in a given time. 1 watt = 1 joule/sec or 10 millions ergs/sec. Example: 102 = 100 log10(100) = 2. When multiplying two numbers, logarithms are added. If no number base given, 10 is assumed. When dividing two numbers, logarithms are subtracted. Can be defined in terms of pressure or power. Reference 20 pa or 0. 0002 dyne/cm2. Always one or more values in comparison.
