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Videos By Chapter
from
Inquiries Into Physics



 

 

 

 

Chapter 6: Waves and Sound

  1. Waves
  2. Wave Propagation
  3. Sound
  4. Production of Sound
  5. Propagation of Sound
  6. Perception of Sound

 

 

Waves and Sound Videos

Waves

Discussion
Streaming
Download
Demo Page
Spring and Rotating Wheel
An oscillating spring shows the y-direction motion of a point on a rotating wheel.

Real

Real

MPG

Wave Propagation

Discussion
Streaming
Download
Demo Page
Shive Wave Machine; wide section, single wave, free end
A wave propagates down the machine. At the free end it is reflected with the same amplitude.

Real

Real

MPG

Shive Wave Machine; wide section, single wave, fixed end
A wave propagates down the machine. At the fixed end it is reflected with the same, but negative amplitude.

Real

Real

MPG

Shive Wave Machine; narrow section, single wave, free end
A wave propagates down the machine. At the free end it is reflected with the same amplitude. The wave on this section moves faster than the wave on the wider section.

Real

Real

MPG

Shive Wave Machine; narrow section, single wave, fixed end
A wave propagates down the machine. At the fixed end it is reflected with the same, but negative amplitude. The wave on this section moves faster than the wave on the wider section.

Real

Real

MPG

Shive Wave Machine; all sections, single wave, free end
A wave propagates down the machine, going from a wide section to a narrow section via a connecting section. As the sections get narrower, the wave travels faster.

Real

Real

MPG

Shive Wave Machine; two sections, single wave, free end
When a wave hits a density barrier, as represented by going from the narrow to the wide section without the connecting section, most of the wave is reflected at the barrier.

Real

Real

MPG

Chladni Plates
When a two dimensional object is vibrated, patterns of waves can be seen. The sand on the plate collects in the nodes, or areas of no motion, of the waves.

Real

Real

MPG

Sound

Discussion
Streaming
Download
Demo Page
Pasco Synthesizer: Pure Tones
A synthesizer is able to produce 'pure' tones, each being a single sine wave.

Real

Real

MPG

Pasco Synthesizer: Chords
A synthesizer is able to produce 'pure' tones, each being a single sine wave. Different cords are created by adding tones.

Real

Real

MPG

Production of Sound

Discussion
Streaming
Download
Demo Page
Guitar: one string
When the string of a guitar are strummed, the cavity and body of the guitar resonate, producing sound.

Real

Real

MPG

Guitar: sonometer, length of string
By adjusting the lengths of a string, different frequencies can be heard.

Real

Real

MPG

Guitar: chords
By adjusting the lengths of several of the strings, different chords can be made.

Real

Real

MPG

Guitar: sonometer, tension of string
By adjusting the tension of a string, different frequencies can be heard.

Real

Real

MPG

Organ Pipe; adjustable, closed end
As the piston is moved out, the standing wave that is set up inside the instrument lengthens, producing a lower pitch.

Real

Real

MPG

Organ Pipe; open end
A standing wave (with an antinode always at the open end) is set up in an organ pipe when air is passed over a slit. Harmonics of this wave can be set up by blowing harder (a LOT harder!).

Real

Real

MPG

Propagation of Sound

Discussion
Streaming
Download
Demo Page
Doppler Tuning Fork; slung
A tuning fork, when slung, will illustrate the doppler shift in frequency. The frequency goes up when the sound is moving towards you while the frequency goes down while it is moving away. .

Real

Real

MPG

Doppler Tuning Fork; rotating
A tuning fork, when rotated, will give a "vibrating" sound illustrating the doppler shift in frequency. The frequency goes up when the sound is moving towards you while the frequency goes down while it is moving away. .

Real

Real

MPG

Doppler Reed
A whistling reed, when rotated, will give a "vibrating" sound illustrating the doppler shift in frequency. The frequency goes up when the sound is moving towards you while the frequency goes down while it is moving away. .

Real

Real

MPG

Doppler Shift, sidewalk observer
The Doppler shift as heard from a passing source:
The frequency of the car's horn goes up when the sound is moving towards you and goes down while it is moving away.

Real

Real

MPG

Doppler Shift, car 1 observer
The Doppler shift as heard from inside the source:
The frequency of the car's horn does not change when you are traveling at the same speed as the source.

Real

Real

MPG

Doppler Shift, car 2 observer
The Doppler shift from a car traveling in the opposite direction as the source:
The frequency of the approaching car's horn goes up when the sound is moving towards you and goes down while it is moving away. Notice that the frequency change is higher in car 2 as compared to the sidewalk.

Real

Real

MPG

Sympathetic Tuning Forks
Sound emanating from one source can be used to excite another source with the same resonance.

Real

Real

MPG

Perception of Sound

Discussion
Streaming
Download
Demo Page
Beats; differential tuning forks
When we hear two tones close in frequency, we experience a vibrato or beat that has the same frequency as the difference of the two tones. For example, if one tuning fork is at 256 Hz and one is at 257 Hz, then we will hear a beat with a frequency of 1 Hz.

Real

Real

MPG

 

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