| DCS # | DEMONSTRATION | REFERENCE | ABSTRACT |
|---|
| 3B30.00 | Wave Properties of Sound | | |
| 3B30.01 | ultrasonic wave phenomena | AJP 38(1),110 | Use 40Khz transducers to show standing waves, spherical propagation, angular distribution, two source interference, etc. by observing the output on an oscilloscope. |
| 3B30.03 | phase of a reflected acoustic wave | AJP 52(9),854 | Note: Physics textbooks incorrectly state that a sound wave reflected at a rigid boundary is 180 degrees out of phase with the incident wave. |
| 3B30.10 | speed of sound by phase difference | PIRA 500 | |
| 3B30.10 | speed of sound by phase difference | 3B30.10 | A function generator drives a speaker. A dual trace oscilloscope displays both the generator output and a microphone signal as the microphone is moved on the lecture bench. |
| 3B30.10 | speed of sound by phase difference | TPT 3(4),170 | An electronic switch is used to show both speaker and microphone traces on a single sweep scope. |
| 3B30.10 | wavelength of sound by phase diff. | Sh-1 | A microphone is moved away from a speaker while an oscilloscope shows the generated and detected sine waves. |
| 3B30.10 | velocity of sound by phase shift | 19-2.1 | Measure the speed of sound by the phase shift of a trace on the oscilloscope as the source is moved back and forth. |
| 3B30.11 | speed of sound by phase difference | TPT 2(8),390 | A microphone is moved back and forth in front of a speaker and the Lissajous figure from the generator and microphone is examined on an oscilloscope. |
| 3B30.11 | speed of sound by phase difference | TPT 3(2),79 | More comments on the TPT 2,390 (1964) article. Additional references. |
| 3B30.12 | sound wave visualization | AJP 52(5),465 | A probe detects the phase difference between the sampling microphone and the speaker and lights either a red or green LED. |
| 3B30.20 | direct speed of sound | PIRA 500 | |
| 3B30.20 | direct speed of sound | 3B30.20 | |
| 3B30.20 | direct speed of sound | AJP 37(2),223 | Striking a gong with a metal rod triggers an oscilloscope and a microphone picks up the sound. |
| 3B30.20 | direct speed of sound | S-3g | Striking a gong with a metal rod triggers an oscilloscope and a microphone picks up the sound. Reference: AJP 37(2),223. |
| 3B30.21 | direct speed of sound | AJP 31(1),xiv | Spark a 10,000 V .02 microF capacitor and pick up the sound with a piezoelectric transducer. |
| 3B30.22 | time of flight | AJP 57(10),920 | A circuit triggers an oscilloscope and coincidentally produces bursts of sound from a speaker. |
| 3B30.23 | time of flight - ultrasonic ranger | AJP 49(6),595 | Polaroid Corporation's ultrasonic ranging system is used as the basis of a time of flight determination of the speed of sound. |
| 3B30.25 | speed of sound by clapping | AJP 48(6),498 | Use a clap,echo,rest,rest sequence with a second student as a director. |
| 3B30.30 | bell in a vacuum | PIRA 200 | Pump air from a bell jar as a battery powered bell rings inside. |
| 3B30.30 | bell in a vacuum | 3B30.30 | Evacuate a bell jar while a ringing bell is suspended inside. |
| 3B30.30 | bell in a vacuum | Sh-2 | A doorbell is placed in a bell jar which is then evacuated. |
| 3B30.30 | bell jar | S-53 | You can hear a bell in a closed jar while air is present. |
| 3B30.30 | bell in a jar | S-52 | Ring a bell in an evacuated bell jar. Other methods and hints. |
| 3B30.30 | bell in a vacuum | S-3a | Air is pumped from a bell jar as a battery powered bell rings inside. |
| 3B30.30 | siren in vacuum | Disc 10-09 | Place an electronic siren with a LED in series in a bell jar. |
| 3B30.40 | speaker and candle | PIRA 1000 | |
| 3B30.40 | speaker and candle | 3B30.40 | Place a candle in front of a large speaker and make the candle flicker with large amplitude low frequency oscillations. |
| 3B30.45 | bubbles and bugle | PIRA 1000 | |
| 3B30.45 | bubbles and bugle | 3B30.45 | Dip a toy bugle in soap solution and blow. The size of the bubble changes imperceptibly. |
| 3B30.50 | helium talking | PIRA 1000 | |
| 3B30.50 | helium talk | 3B30.50 | Sing, talk or laugh while breathing helium. |
| 3B30.50 | meduim and speed of sound | S-86 | Fill your lungs with hydrogen or helium and speak or sing. |
| 3B30.50 | sound in helium | Disc 10-14 | Blow an organ pipe with air and helium, then talk with helium. |
| 3B30.51 | medium and speed of sound | S-85 | Two organ pipes are adjusted to unison, then one is filled with hydrogen. A long tube is attached to a whistle and when the gas reaches it the pitch rises. |
| 3B30.52 | speed of sound in liquid | AJP 39(3),340 | Shop drawings and circuit diagram for a ultrasonic echo pulse chamber for measuring the velocity of sound in liquids. Designed for laboratory use. |
| 3B30.52 | medium and speed of sound with PZT | TPT 28(2),125 | Use a piezoelectric element as a detector for measuring the speed of sound in solids and liquids. |
| 3B30.53 | speed of sound in liquid | AJP 41(3),433 | An ultrasonic transducer is pulsed in a liquid cavity and the initial and reflected pulses are observed on an oscilloscope. |
| 3B30.53 | modified circuit | AJP 45(6),588 | Add a simple circuit to chop the initial pulse down to a low value, preventing amplifier overload. |
| 3B30.55 | sound velocity at different temperatures | PIRA 1000 | |
| 3B30.55 | temp and speed of sound | S-83 | Two organ pipes are blown simultaneously and then the air in one is heated by an internal coil. |
| 3B30.55 | temp and speed of sound | S-84 | Two whistles of the same pitch are blown and one is then heated with a match. |
| 3B30.55 | sound velocity of different temperat | Disc 10-13 | Blow two identical organ pipes from the same source, then heat the air going to one of the pipes with a Bunsen burner. |
| 3B30.56 | velocity of sound with temperature | 19-2.4 | Attach a whistle to a coil of copper tubing placed in liquid nitrogen. |
| 3B30.60 | speed of sound in rod and air | PIRA 1000 | |
| 3B30.60 | speed of sound in rod and air | 3B30.60 | Hit a twelve foot aluminum rod on one end with a hammer. Trigger an oscilloscope with a microphone at the hammer end display the signal from microphones at the end of the rod and at the same distance. |
| 3B30.61 | velocity of sound in a rod | 19-2.3 | A timer is triggered by metal balls bouncing off brass blocks mounted one meter apart on a brass rod when one end of the rod is struck with a hammer. |
| 3B30.62 | direct speed of sound in a rod | AJP 38(9),1151 | A bell clapper hits one end of a rod and triggers an oscilloscope, a phonograph needle and crystal pickup on the other end generates a signal that is displayed on the scope. |
| 3B30.65 | music box | PIRA 1000 | |
| 3B30.65 | music box | 3B30.65 | Sound is transmitted through a long wood rod from a music box in the basement to a sounding box in the classroom. |
| 3B30.65 | transmission of sound through wood | Sf-3 | A long 1"x1" wood bar is placed on top of a music box in the basement, through a hole in the floor, to a sounding box in the classroom. |
| 3B30.66 | medium and speed of sound | S-87 | Stand near a railroad track and listen as a hammer is struck against the rail 200' away. |