1-7 How Does A Sound Wave Work?
What Does A Sound Wave Look Like?
A sound wave can be pictured as pressure variations within a medium.
Parts of the Sound Wave
Amplitude- the change in pressure variation above and below the atmospheric pressure
Wavelength- distance between the centers of 2 adjacent compressions
Frequency- the number of compressions that pass a particular point in the tube at a given time
Speed- represented by the symbol v
= distance advanced/ time it takes to advance
= wavelength / T
Also, since T = 1/f:
v = (1/T) times wavelength
so v = f times wavelength
Practice Problems:
1. An automatic focus camera is able to focus on objects by use of an ultrasonic sound wave. The camera sends out sound waves that reflect off distant objects and return to the camera. A sensor detects the time it takes for the waves to return and then determines the distance an object is from the camera. If a sound wave (speed = 340 m/s) returns to the camera 0.150 seconds after leaving the camera, how far away is the object?
2. On a hot summer day, a pesky little mosquito produced its warning sound near your ear. The sound is produced by the beating of its wings at a rate of about 600 wing beats per second.
(a) What is the frequency in Hertz of the sound wave?
(b) Assuming the sound wave moves with a velocity of 350 m/s, what is the wavelength of the wave?
3. Playing middle C on the piano keyboard produces a sound with a frequency of 256 Hz. Assuming the speed of sound in air is 345 m/s, determine the wavelength of the sound corresponding to the note of middle C.
4. An elephant produces a 10 Hz sound wave. Assuming the speed of sound in air is 345 m/s, determine the wavelength of this infrasonic sound wave.
Continue: #REDIRECT 1-8 Sound Wave Characteristics
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