2. Look up an approximate value for the speed in air (at a temperature of 20°C) for 49 kHz ultrasound. [Hint: Ultrasound is still sound, so you will need to search for the velocity of sound at different frequencies in the CRC Handbook available from TTU Library-3rd Floor, call number: QD65 .H3 or online.] Record your value in m/s and give the source of your information. Photocopy the page from which you gọt your information and include it when you turn in your preliminary questions. Alternatively, you can take a picture and print it out.

2. Look up an approximate value for the speed in air (at a temperature of 20°C) for 49 kHz ultrasound. [Hint: Ultrasound is still sound, so you will need to search for the velocity of sound at different frequencies in the CRC Handbook available from TTU Library-3rd Floor, call number: QD65 .H3 or online.] Record your value in m/s and give the source of your information. Photocopy the page from which you gọt your information and include it when you turn in your preliminary questions. Alternatively, you can take a picture and print it out.

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN:9781305116399

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter17: Sound Waves

Section: Chapter Questions

Problem 17.12OQ: With a sensitive sound-level meter, you measure the sound of a running spider as -10 dB. What does...

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Similar questions

Table 17.1 shows the speed of sound is typically an order of magnitude larger in solids than in gases. To what can this higher value be most directly attributed? (a) the difference in density between solids and gases (b) the difference in compressibility between solids and gases (c) the limited size of a solid object compared to a free gas (d) the impossibility of holding a gas under significant tension
Suppose a person has a 50—UB hearing loss at all frequencies. By how many factors of 10 will low—intensity sounds need to be ampli?ed to seem normal to this person? Note that smaller amplification is appropriate for more intense sounds to avoid further hearing damage.
Write an expression that describes the pressure variation as a function of position and time for a sinusoidal sound wave in air. Assume the speed of sound is 343 m/s, = 0.100 m, and Pmax = 0.200 Pa.
Suppose a bat uses sound echoes to locate its insect prey, 3.00 m away. (See Figure 17.10.) (a) Calculate the echo times for temperatures of 5.00°C and 35.0°C. (b) What percent uncertainty does this cause for the bat in locating the insect? (c) Discuss the significance of this uncertainty and whether it could cause difficulties for the bat. (In practice, the hat continues to use sound as it closes in, eliminating most of any dif?culties imposed by this and other effects, such as motion of the prey.) Figure 17.10 A bat uses sound echoes to find its way about and to catch prey. The time for the echo to return is directly proportional to the distance.
(a) What are the loudnesses in phons of sounds having frequencies of 200, 1000, 5000, and 10,000 Hz. if they are all at the same 60.0dB sound intensity level? (b) If may are all at 110 dB? (c) If they are all at 20.0 dB?
What frequency sound has a 0.10m wavelength when the speed of sound is 340 m/s?
What are the closest frequencies to 500 Hz that an average person can clearly distinguish as being different in frequency from 500 Hz? The sounds are not present simultaneously.
With a sensitive sound-level meter, you measure the sound of a running spider as -10 dB. What does the negative sign imply? (a) The spider is moving away from you. (b) The frequency of the sound is too low to be audible to humans. (c) The intensity of the sound is too faint to be audible to humans. (d) You have made a mistake; negative signs do not fit with logarithms.
Based on the graph in Figure 17.36, what is the threshold of hearing in decibels for frequencies of 60, 400, 1000, 4000, and 15,000 Hz? Note that many AC electrical appliances produce 60 Hz, music is commonly 400 Hz, a reference frequency is 1000 Hz, your maximum sensitivity is near 4000 Hz, and many older TVs produce a 15,750 Hz whine. Figure 17.36 The relationship of loudness in phons to intensity level (in decibels) and intensity (in watts per meter squared) for persons with normal hearing. The curved lines are equal-loudness curves—all sounds on a given curve are perceived as equally loud. Phons and decibels are defined to be the same at 1000 Hz.