| vw = fl |
|
T = 1 / f |
|
d = r t |
| Doppler Effect |
|
source moving:
Dl / l = v / vw
listener moving: Df / f = v / vw |
|
towards listener, crowded
wavelengths Þ higher
f
away from listener, wavelengths pulled apart Þ lower f
towards source,
encounter waves in less time Þ higher f
away from source, encounter waves in more time Þ lower f |
| Sound level |
|
SLdB
= 10 log10 ( I / Io ) |
|
Io = 1 x 10-12 watts/m² |
| Beats |
|
beat frequency = | f2
- f1 |
|
|
beat pitch = ½ ( f1
+ f2 ) |
| EPD |
|
constructive
interference (loud)
destructive interference (minimal) |
|
EPD = ml
EPD = ½ (2m - 1) lwhere m is a counter {1,2,3....} |
| speed of sound in dry
air |
|
vw = 331.5 +
0.6 T |
|
|
(strings)
 |
|
(pendulum)
T = 2p
[ L / g] |
|
(standing
waves)
loop = ½l |
open-open pipe
rods only clamped at their centers |
|
fn = ( n + 1 ) fo |
|
for the fundamental
A-N-A
L = 1 loop = ½l |
| open-closed pipe |
|
fn = ( 2n +
1 ) fo |
|
for the fundamental
A-N
L = ½ loop = ¼l |
| clamped-clamped wire |
|
fn = ( n + 1
) fo |
|
for the fundamental
N-A-N
L = 1 loop = ½l |
