This article may be
confusing or unclear to readers. (July 2018) |
In a compressible sound transmission medium - mainly air - air particles get an accelerated motion: the particle acceleration or sound acceleration with the symbol a in metre/second2. In acoustics or physics, acceleration (symbol: a) is defined as the rate of change (or time derivative) of velocity. It is thus a vector quantity with dimension length/ time2. In SI units, this is m/s2.
To accelerate an object (air particle) is to change its velocity over a period. Acceleration is defined technically as "the rate of change of velocity of an object with respect to time" and is given by the equation
This equation gives a the units of m/(s·s), or m/s2 (read as "metres per second per second", or "metres per second squared").
An alternative equation is:
Transverse acceleration (perpendicular to velocity) causes change in direction. If it is constant in magnitude and changing in direction with the velocity, we get a circular motion. For this centripetal acceleration we have
One common unit of acceleration is g-force, one g being the acceleration caused by the gravity of Earth.
In classical mechanics, acceleration is related to force and mass (assumed to be constant) by way of Newton's second law:
The Particle acceleration of the air particles a in m/s2 of a plain sound wave is:
Symbol | Units | Meaning |
---|---|---|
a | m/ s2 | particle acceleration |
v | m/s | particle velocity |
δ | m, meters | particle displacement |
ω = 2πf | radians/ s | angular frequency |
f | Hz, hertz | frequency |
p | Pa, pascals | sound pressure |
Z | N· s/m3 | acoustic impedance |
J | W/m2 | sound intensity |
E | W· s/m3 | sound energy density |
Pac | W, watts | sound power or acoustic power |
A | m2 | area |
This article may be
confusing or unclear to readers. (July 2018) |
In a compressible sound transmission medium - mainly air - air particles get an accelerated motion: the particle acceleration or sound acceleration with the symbol a in metre/second2. In acoustics or physics, acceleration (symbol: a) is defined as the rate of change (or time derivative) of velocity. It is thus a vector quantity with dimension length/ time2. In SI units, this is m/s2.
To accelerate an object (air particle) is to change its velocity over a period. Acceleration is defined technically as "the rate of change of velocity of an object with respect to time" and is given by the equation
This equation gives a the units of m/(s·s), or m/s2 (read as "metres per second per second", or "metres per second squared").
An alternative equation is:
Transverse acceleration (perpendicular to velocity) causes change in direction. If it is constant in magnitude and changing in direction with the velocity, we get a circular motion. For this centripetal acceleration we have
One common unit of acceleration is g-force, one g being the acceleration caused by the gravity of Earth.
In classical mechanics, acceleration is related to force and mass (assumed to be constant) by way of Newton's second law:
The Particle acceleration of the air particles a in m/s2 of a plain sound wave is:
Symbol | Units | Meaning |
---|---|---|
a | m/ s2 | particle acceleration |
v | m/s | particle velocity |
δ | m, meters | particle displacement |
ω = 2πf | radians/ s | angular frequency |
f | Hz, hertz | frequency |
p | Pa, pascals | sound pressure |
Z | N· s/m3 | acoustic impedance |
J | W/m2 | sound intensity |
E | W· s/m3 | sound energy density |
Pac | W, watts | sound power or acoustic power |
A | m2 | area |