6) Sound

a) Doppler Effect

Set of four round plastic disks that can be overlaid to show Doppler-effect. Rotating whistle to hear the change in pitch. Simple childs toy that can be used to hear the change in pitch. Toy resonant tube.
Also shows change in pitch. b) Interference Two speakers mounted on a stand the produces the same sound, they can be rotated so that
students can hear the interference pattern. Tuning forks mounted on resonant boxes of slightly different frequencies. Similar to above but more like Xylophone like Portable radio attached to a small speaker.
The card has a hole the size of the speaker, which blends out he interference of the sound
Waves from the back of the speaker, dramatically increasing the quality of the sound
output. c) Resonance and Standing Waves                           A metal plate that is played with a violin bow and shows interesting pattern of nodal/
                          Antinodal points on the plate A Fine crystal glass that sings when rubbed with your finger. Sets up resonant wave pattern
in glass. A corrugated toy tube that sings when spun in circles. Five harmonics can be heard. Tubes that have a small mesh screens at the base.
If the mesh is heated it causes hot air to oscillate in the tube as it rises and produces sound. A six Foot tube that has gas jets along the top and a speaker mounted on one end.
It shows standing waves created in sound by a flaming wave on top of the tube.(high gas pressure=peak time) A vertical tube filled with water where the water level can be adjusted to change the length
of the resonant chamber.
A tuning fork is held at the open end of the tube and its wavelength can be measured by
listening for its resonance. Tube filled with a fine powder and has a speaker attached at one end.
The sound waves causes the powder to collect at the nodal points. Pipes of different length can be used with a tuning fork to show resonance with open or
closed tubes. A metal chalice mounted next to an adjustable closed tube.
The size of the resonant chamber can be changed to tune in resonance. Shows a red ball bouncing of a piston attached to the rotator.
The resonant frequency of the balls bounce is found by changing the speed of the rotator. d) Instruments Bottles filled with water that can be blown on to produce sound. e) Others A computer sound digitizer and analyzer.
A large screen can be display the computer output to show the shape of sound waves and
a spectrum analysis of complicated sound. A chart that shows the frequency range of various instruments.                           A bell producing sound waves and light producing electromagnetic waves are contained
                          in a vacuum jar
                          The light transmits through the vacuum but he sound cannot be heard. A guitar-like stringed sounding board used to discuss length and the frequency of the sound
produced. Breathe helium to show how your voice changes with a different speed of sound.