Name ___________________________________________ Date ________________ Period _________ P HYSICS P ART I – S URFING THE W AVES Wave Theory Waves transfer ________ through a medium. The __________ doesn’t move – the energy does. Longitudinal Wave Wave Types Molecules move _________________________ as the wave. Transverse Wave Molecules move ________________ to the direction of the wave.

Actual Wave How we can think of it Wavelength – Amplitude = Pitch velocity = wavelength x frequency v = λ ƒ Velocity is constant As frequency increases, _____________________________. As wavelength increases, ____________________________.

Interference Standing Wave In a closed tube, the wave _________________________. Waves of a ________ frequency than the fundamental – add richness to tones. Different instruments accentuate different ____________. Overtones

Loudness Measured in __________ – indicate the amplitude of the wave. Source of soundSound pressure level Sound in airdB re 20 μPa Shockwave (distorted sound waves > 1 atm; waveform valleys are clipped at zero pressure)atm>194 dB Theoretical limit for undistorted sound at 1 atmosphere environmental pressure~ dB Stun grenades170–180 dB Rocket launch equipment acoustic tests~165 dB Simple open-ended thermoacoustic device [6] [6] 176 dB rifle being fired 1 m to shooter's side171 dB (peak) M1 Garand rifle being fired at 1 m168 dB Jet engine at 30 m150 dB Threshold of pain130 dB Vuvuzela horn at 1 m120 dB(A) [7] [7] Hearing damage (possible)approx. 120 dB Jet engine at 100 m110 – 140 dB Non-electric chainsaw at 1 m110 dB [8] [8] Jack hammer at 1 mapprox. 100 dB Traffic on a busy roadway at 10 m80 – 90 dB Hearing damage (over long-term exposure, need not be continuous)85 dB [9] [9] Passenger car at 10 m60 – 80 dB EPA-identified maximum to protect against hearing loss and other disruptive effects from noise, such as sleep disturbance, stress, learning detriment, etc. 70 dB [10] [10] Handheld electric mixer65 dB TV (set at home level) at 1 mapprox. 60 dB Washing machine, dishwasher42-53 dB [11] [11] Normal conversation at 1 m40 – 60 dB Very calm room20 – 30 dB Light leaf rustling, calm breathing10 dB Auditory threshold at 1 kHz0 dB [9] [9] The Human Ear