SPA 3032 AcousticsTerms-gray

SPA 3032 AcousticsTerms-gray - Acoustics - Common Terms...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Acoustics - Common Terms Frequency (1/period) Time (period) Pressure - dynes/cm2 Intensity - Watts/m2 Sinusoidal Complex Stimuli (Speech) Filtering Resonance Physical Principles Length - meters Time - seconds or milliseconds (msec) Mass - kilograms Fundamental Physical Quantities System MKS CGS Length M(eter) C(entimeter Mass K(ilogram) G(ram) Time S(econd) S(econd) Fundamental Physical Quantities Time msec (millisecond) = 10-3 usec (microsecond) = 10-6 sec or 10-3 msec Length km (kilometer = 103 m (meters) cm (centimeters) = 10-2 m mm (millimeter) = 10-3 m or 10-1 cm u or um (micron or micrometer) = 10-6 m or 10-3 mm Mass kg (kilogram = 103 g or 10-3 kg mg (milligram) = 10-3 g Derived Physical Quantities Area - m2 Volume - m3 Velocity - m/sec speed - m/hr or m/sec Acceleration - m/sec2 Force - Newtons or dynes Pressure - pascals or bars or PSI Work - joules Power - watts Intensity - watts/m2 Definitions Displacement - movement of an object from one place to another. It has both magnitude and direction (vector quantity). Magnitude - maximum displacement on either side of equilibrium. Definitions Velocity - the rate at which the object's displacement is changing (vector). Speed - units of distance covered in one unit of time. S = d/t Acceleration - rate at which an object's velocity is changing (meters/sec2) Force A push or pull when applied to a mass will cause acceleration. Gravity is a constant force Unit of measure of force is mass x acceleration (f = m x a) Force Newton = force required to move one kg with an acceleration of one meter/sec2 N = kg x m/sec2 (MKS metric system) Dyne = a much smaller force or that force required to move one gram with an acceleration of one cm/sec2 (d = g x cm/sec2) (cgs metric system) Pressure A force spread over one unit of area Unit of pressure = Newton/meter2 (n/m2) Pascal (Pa) = 1N/m2 Or - we can refer to dynes/cm2 = microbar (a much smaller pressure) Or we can refer to pounds per square inch (PSI) Work Force x distance. Joule(j) = unit of work = force of one newton acting through a distance of one meter Power Rate at which work is done. It can be measured in joules per second which is called watts. One watt = one joule of work per second. Acoustic Intensity Rate at which acoustic power passes through an area. Watts/m2 METRIC SYSTEMS Force CGS MKS dyne Newton Sound Pressure dynes/cm2 Newton/m2 SPL Reference 0.0002 dynes/cm2 20uPa ...
View Full Document

Ask a homework question - tutors are online