Transcript Physics Part I Notes

Name ___________________________________________
Date ________________ Period _________
PHYSICS PART I – SURFING THE WAVES
Wave Theory
Waves transfer ________ through a medium.
The __________ doesn’t move – the energy does.
Wave Types
Longitudinal Wave
Molecules move _________________________ as the wave.
Transverse Wave
Molecules move ________________ to the direction of
the wave.
Actual Wave
How we can think of it
Amplitude =
Wavelength –
Pitch
velocity = wavelength x frequency
v=λƒ
Velocity is constant
As frequency increases, _____________________________.
As wavelength increases, ____________________________.
Interference
Standing Wave
In a closed tube, the wave _________________________.
Overtones
Waves of a ________ frequency than the fundamental –
add richness to tones.
Different instruments accentuate different ____________.
Loudness
Measured in __________ – indicate the amplitude of the
wave.
Source of sound
Sound in air
Shockwave (distorted sound waves > 1 atm; waveform valleys are clipped at zero pressure)
Theoretical limit for undistorted sound at 1 atmosphere environmental pressure
Stun grenades
Rocket launch equipment acoustic tests
Simple open-ended thermoacoustic device[6]
.30-06 rifle being fired 1 m to shooter's side
M1 Garand rifle being fired at 1 m
Jet engine at 30 m
Threshold of pain
Vuvuzela horn at 1 m
Hearing damage (possible)
Jet engine at 100 m
Non-electric chainsaw at 1 m
Jack hammer at 1 m
Traffic on a busy roadway at 10 m
Hearing damage (over long-term exposure, need not be continuous)
Passenger car at 10 m
EPA-identified maximum to protect against hearing loss and other disruptive effects from noise,
such as sleep disturbance, stress, learning detriment, etc.
Handheld electric mixer
TV (set at home level) at 1 m
Washing machine, dishwasher
Normal conversation at 1 m
Very calm room
Light leaf rustling, calm breathing
Auditory threshold at 1 kHz
The Human Ear
Sound pressure level
dB re 20 μPa
>194 dB
~194.094 dB
170–180 dB
~165 dB
176 dB
171 dB (peak)
168 dB
150 dB
130 dB
120 dB(A)[7]
approx. 120 dB
110 – 140 dB
110 dB[8]
approx. 100 dB
80 – 90 dB
85 dB[9]
60 – 80 dB
70 dB[10]
65 dB
approx. 60 dB
42-53 dB[11]
40 – 60 dB
20 – 30 dB
10 dB
0 dB[9]