Question 1

When a tuba is played,the player makes a buzzing sound and blows into one end of a tube that has an effective length of 3.50 m.The other end of the tube is open.If the speed of sound in air is 343 m/s,what is the lowest frequency the tuba can produce?

Accepted Answer

A) 8.00 Hz 
B) 12.0 Hz 
C) 16.0 Hz 
D) 24.0 Hz 
E) 49.0 Hz

Question 2

A certain string,clamped at both ends,vibrates in seven segments at a frequency of 2.40 × 10² Hz.What frequency will cause it to vibrate in four segments?

Accepted Answer

A) 89 Hz 
B) 137 Hz 
C) 274 Hz 
D) 411 Hz 
E) 420 Hz

Question 3

A cylindrical tube sustains a fundamental frequency f₁ when both of its ends are open.A second cylindrical tube with one end closed has the same fundamental frequency.What is the ratio of the length of the second tube to that of the first,

Accepted Answer

A) 0.5 
B) 4 
C) 2 
D) 0.25 
E) 1

Question 4

A speaker generates a continuous tone of 440 Hz.In the drawing,sound travels into a tube that splits into two segments,one longer than the other.The sound waves recombine before being detected by a microphone.The speed of sound in air is 339 m/s.What is the minimum difference in the lengths of the two paths for sound travel if the waves arrive exactly out of phase at the microphone?

Accepted Answer

A) 0.10 m 
B) 0.39 m 
C) 0.77 m 
D) 1.11 m 
E) 1.54 m

Question 5

When plucked,a 0.62-m guitar string produces a sound wave with a fundamental frequency of 196 Hz.The speed of sound in air is 343 m/s.Determine the ratio of the wavelength of the sound wave to the wavelength of the waves that travel on the string.

Accepted Answer

A) 0.071 
B) 0.28 
C) 0.49 
D) 1.4 
E) 2.0

Question 6

A guitar string has a linear density of 8.30 × 10-⁴ kg/m and a length of 0.660 m.The tension in the string is 56.7 N.When the fundamental frequency of the string is sounded with a 196.0-Hz tuning fork,what beat frequency is heard?

Accepted Answer

A) 6 Hz 
B) 4 Hz 
C) 12 Hz 
D) 8 Hz 
E) 2 Hz

Question 7

Water waves approach an aperture.The resulting patterns are shown for two different cases,A and B,in which the wavelength and aperture size are varied.  Which one of the following statements concerning these cases is true?

Accepted Answer

A) Neither figure shows diffraction.In both cases,the wavelength is much smaller than the aperture. 
B) Diffraction occurs in A,but not in B because the wavelength in A is much smaller than the aperture. 
C) Diffraction occurs in B,but not in A because the wavelength in B is much smaller than the aperture. 
D) Both figures show diffraction.In both cases,the wavelengths are approximately the same size as the aperture. 
E) Diffraction occurs in B,but not in A because the wavelength in B is approximately the same size as the aperture.

Question 8

The figures show standing waves of sound in six organ pipes of the same length.Each pipe has one end open and the other end closed.Note: some of the figures show situations that are not possible.
-If the length of the pipes is 0.500 m,what is the frequency of the sound emitted from pipe 3? The speed of sound is 343 m/s.

Accepted Answer

A) 172 Hz 
B) 344 Hz 
C) 429 Hz 
D) 515 Hz 
E) 858 Hz

Question 9

Two pulses of identical shape travel toward each other in opposite directions on a string,as shown in the drawing.Which one of the following statements concerning this situation is true?

Accepted Answer

A) The pulses will reflect from each other. 
B) The pulses will diffract from each other. 
C) The pulses will interfere to produce a standing wave. 
D) The pulses will pass through each other and produce beats. 
E) As the pulses pass through each other,they will interfere destructively.

Question 10

A 6.00-m long string sustains a three-loop standing wave pattern as shown.The wave speed is 2.00 × 10² m/s.
 
-What is the lowest possible frequency for standing waves on this string?

Accepted Answer

A) 50.0 Hz 
B) 33.3 Hz 
C) 25.0 Hz 
D) 16.7 Hz 
E) 8.33 Hz

Question 11

A string with a length of 3.0 m has two adjacent resonances at frequencies 112 Hz and 140 Hz.
-How many antinodes will be found on the 112 Hz resonance?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 12

A string with a linear density of 0.035 kg/m and a mass of 0.014 kg is clamped at both ends.Under what tension in the string will it have a fundamental frequency of 110 Hz?

Accepted Answer

A) 270 N 
B) 310 N 
C) 450 N 
D) 580 N 
E) 690 N

Question 13

Two traveling pulses on a rope move toward each other at a speed of 1.0 m/s.The waves have the same amplitude.The drawing shows the position of the waves at time t = 0 s.Which one of the following drawings depicts the waves on the rope at t = 2.0 s?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e

Question 14

A string with a length of 3.0 m has two adjacent resonances at frequencies 112 Hz and 140 Hz.
-Determine the speed of the waves on the string vibrating at 140 Hz..

Accepted Answer

A) 28 m/s 
B) 42 m/s 
C) 56 m/s 
D) 140 m/s 
E) 168 m/s

Question 15

Four standing wave segments,or loops,are observed on a string fixed at both ends as it vibrates at a frequency of 240 Hz.What is the fundamental frequency of the string?

Accepted Answer

A) 23 Hz 
B) 28 Hz 
C) 35 Hz 
D) 60 Hz 
E) 80 Hz

Question 16

A pebble is dropped in a lake;and it produces ripples with a frequency of 0.50 Hz.When should a second pebble be dropped at the same place to produce destructive interference?

Accepted Answer

A) 0.50 s after the first 
B) 0.75 s after the first 
C) 1.0 s after the first 
D) 1.5 s after the first 
E) 2.0 s after the first

Question 17

For a diffraction horn loudspeaker,sound emerges through a rectangular opening.The opening of a diffraction horn has a width of 0.12 m.If the speaker emits a continuous tone with a wavelength of 0.09 m,at what angle does the first minimum occur?

Accepted Answer

A) 47° 
B) 39° 
C) 23° 
D) 12° 
E) 66°

Question 18

One string on a guitar is exactly in tune.The guitarist uses this string to produce a tone with a frequency of 196 Hz by pressing down at the proper fret.An adjacent string can also be used to produce this tone without being pressed against a fret.However,this adjacent string is out of tune and produces a tone that sounds lower in frequency than the other tone.When the tones are produced simultaneously,the beat frequency is 5.0 Hz.What frequency does the adjacent string produce?

Accepted Answer

A) 196 Hz 
B) 191 Hz 
C) 171 Hz 
D) 201 Hz 
E) 186 Hz

Question 19

A speaker is designed for wide dispersion for a high frequency sound.What should the diameter of the circular opening be for a speaker where the desired diffraction angle is 11° and a 9100 Hz sound is generated? The speed of sound is 343 m/s.

Accepted Answer

A) 0.039 m 
B) 0.077 m 
C) 0.24 m 
D) 0.13 m 
E) 0.048 m

Question 20

A cylindrical tube sustains standing waves at the following frequencies: 600 Hz,800 Hz,and 1000 Hz.The tube does not sustain standing waves at 500 Hz,at 900 Hz,at any frequencies between 600 and 800 Hz,or at any frequencies between 800 and 1000 Hz.Determine the fundamental frequency of the tube and whether the tube is open at both ends or has only one end open.

Accepted Answer

A) 50 Hz,both ends 
B) 100 Hz,one end 
C) 100 Hz,both ends 
D) 200 Hz,one end 
E) 200 Hz,both ends

Exam 17: The Principle of Linear Superposition and Interference Phenomena