\(\def \u#1{\,\mathrm{#1}}\)
\(\def \abs#1{\left|#1\right|}\)
\(\def \ast{*}\)
\(\def \deg{^{\circ}}\)
\(\def \tau{\uptau}\)
\(\def \ten#1{\times 10^{#1}}\)
\(\def \redcancel#1{{\color{red}\cancel{#1}}}\)
\(\def \BLUE#1{{\color{blue} #1}}\)
\(\def \RED#1{{\color{red} #1}}\)
\(\def \PURPLE#1{{\color{purple} #1}}\)
\(\def \th#1,#2{#1,\!#2}\)
\(\def \lshift#1#2{\underset{\Leftarrow\atop{#2}}#1}}\)
\(\def \rshift#1#2{\underset{\Rightarrow\atop{#2}}#1}}\)
\(\def \dotspot{{\color{lightgray}{\circ}}}\)
\(\def \ccw{\circlearrowleft}\)
\(\def \cw{\circlearrowright}\)
How Things Move
Why Things Move
pulse
medium
transverse
longitudinal
wave
period
frequency
sinusoidal waves
snapshot
crests
troughs
in phase
out of phase
wavelength
wave equation
\(v={\lambda\over T}\)
\(v=\lambda f\)
compression
rarefaction
pressure waves
loudness
pitch
fundamental frequency
overtones
superposition
constructive interference
destructive interference
path length
\(\ell = {L\over \lambda}\)
If \(\Delta\ell\) is an integer, we have constructive interference.
If \(\Delta\ell\) is an integer plus 0.5, we have destructive interference.
doppler effect
If source and observer are moving towards each other, the frequency will increase.
If source and observer are moving away from each other, the frequency will decrease.
\(f_{obs} = f_{src}{v_w\mp v_{obs}\over v_w\pm v_{src}}\)
intensity
sound intensity level
bels
decibels
\(\beta = 10\u{dB}(\log_{10}I+12)\)
\(\beta_N = \beta_1 + 10\log_{10}N\)
\(\beta(r') = \beta(r) - 20\log_{10}{r'\over r}\)