Week 32 Assignment 2013-2014
name________________
1. - Question Details Giancoli5 11.P.035. [7372]
A sound wave in air has a frequency of 263 Hz and travels with a speed of 330 m/s. How far apart are the
wave crests (compressions)?
1.25m
2. - Question Details Giancoli5 11.P.034. [303197]
A fisherman notices that wave crests pass the bow of his anchored boat every 5.2 s. He measures the
distance between two crests to be 8.3 m. How fast are the waves traveling?
1.6m/s
3. - Question Details Giancoli5 11.P.036. [7373]
AM radio signals have frequencies between 550 kHz and 1600 kHz (kilohertz) and travel with a speed of
3.00 ✕ 108 m/s. What are the wavelengths of these signals?
550 kHz signal
545m
1600 kHz signal
188m
On FM, the frequencies range from 88.0 MHz to 108 MHz (megahertz) and travel at the same speed. What
are their wavelengths?
88.0 MHz signal
3.41m
108 MHz signal
2.78m
4. - Question Details Waves Doppler 1 [1731948]
4. A car's horn produces a frequency of 478 Hz when at rest. The car is moving at 45.3 m/s, and the air
temperature is 15.7° C.
A. What is the speed of sound in air at this temperature?
3.40e+02 m/s
B. What is the apparent frequency to an observer at A?
551 Hz
C. What is the apparent wavelength to an observer at A?
0.617 m
D. What is the apparent frequency to an observer at R?
422 Hz
E. What is the apparent wavelength to an observer at R?
0.807 m
5. - Question Details Giancoli5 12.P.026. [68925]
The G string on a violin has a fundamental frequency of 196 Hz. The length of the vibrating portion is 32
cm and has a mass of 0.40 g. Under what tension must the string be placed?
19.7N
6. - Question Details Giancoli5 12.P.037. [185345]
A uniform narrow tube 1.60 m long is open at both ends. It resonates at two successive harmonics of
frequency 280 Hz and 420 Hz. What is the speed of sound in the gas in the tube?
448m/s
7. - Question Details Giancoli5 12.P.054. [7500]
Two automobiles are equipped with the same single-frequency horn. When one is at rest and the other is
moving toward an observer at 13 m/s, a beat frequency of 5.2 Hz is heard. What is the frequency the horns
emit? Assume T = 20°C.
132Hz
8. - Question Details Giancoli5 12.P.023. [68924]
A 10000 Hz tone must have what intensity level to seem as loud
as a 500 Hz tone that has a 80 dB sound level? (See Fig. 12-7.)
90dB
Figure 12-7.
9. - Question Details Giancoli5 11.P.075. [7413]
Two strings on a musical instrument are tuned to play at 262 Hz (C) and 294 Hz (D).
(a) What are the first two overtones for each string?
first overtone for C
524Hz
second overtone for C
786Hz
first overtone for D
588Hz
second overtone for D
882Hz
(b) If the two strings have the same length and are under the same tension, what must be the ratio of their
masses (MC/MD)? 1.26
(c) If the strings, instead, have the same mass per unit length and are under the same tension, what is the
ratio of their lengths (LC/LD)?
1.12
(d) If their masses and lengths are the same, what must be the ratio of the tensions in the two strings?
(TC/TD) 0.794
10. - Question Details Waves sonometer 1 [1733713]
A sonometer is used to check the resonant frequencies of tuning forks.
First, a known tuning fork of frequency 304 Hz is used, and the sonometer resonates when the air column
height is 27.9 cm.
A. What is the resonant wavelength at this frequency?
B. What is the speed of sound in the room?
1.11 m
339 m/s
C. What is the temperature of the air in the room?
13.0°
Then an unknown tuning fork is used,and it resonates at an air column height of 19.2 cm.
D. What is the resonant wavelength of this frequency? 0.767 m
E. What is the frequency of the unknown tuning fork?
442 Hz