Chapter 14: Sound Waves
Intensity of sound - measured in decibels
Sound wave propagates outward in all directions, so the intensity decreases
with distance I ~ 1/r^2
How much more intense is a 60 dB sound compared to a 40 dB sound?
Doppler effect: An electronic buzzer emits a constant tone. Why does the pitch vary when the buzzer is twirled horizontally but not vertically?
Resonance in a half-closed tube occurs for a 256 Hz (middle C) tuning
fork when L = 32 cm. Why?
What is the shortest length of tube that will produce resonance for
a 480 Hz tuning fork? What is the next longest length of tube that
will support a standing wave with this same tuning fork?
Why are car radio antennas about 3/4 of a meter long?
Whirly tube: Why does the tube produce distinctly different tones when twirled slow and then fast? What is the mathematical relationship between these tones? How can the frequency of the tones be determined by knowing that the tube is 80 cm long?
Speed of sound:
How does the speed of sound depend on frequency?
How does the speed of sound depend on the density of the medium through
which the sound travels?
Does the speed of sound increase or decrease when the air temperature
rises?
How can we break the sound barrier in this classroon?
How can the speed of an F-14 be determined
by viewing the shock wave?