Question 1

An organ pipe open at both ends has two successive harmonics with frequencies of  and  .What is the length of the pipe? The speed of sound is  in air.

Accepted Answer

The fundamental frequency of an open organ pipe is given by:

f1 = v/2L

Where v is the speed of sound and L is the length of the pipe.

The two successive harmonics are given by:

f2 = 2f1 = v/L and f3 = 3f1 = 3v/2L

We can solve for L by setting f2 and f3 equal to the given frequencies and solving for L:

v/L = 11ea83ea_6a0e_ebbb_aeff_9f842bfec076_TB6394_11

3v/2L = 11ea83ea_6a0e_ebba_aeff_157e9239a33d_TB6394_11

Dividing the second equation by the first and simplifying, we get:

1.5 = 11ea83ea_6a0e_ebba_aeff_157e9239a33d_TB6394_11 /11ea83ea_6a0e_ebbb_aeff_9f842bfec076_TB6394_11

1.5 = 10.83333

L = v/(1.5*f2) = 5.73 m

Therefore, the answer is B) 5.73 m.

Question 2

A pipe that is 0.46 m long and open at both ends vibrates in the second overtone with a frequency of  In this situation,the distance from the center of the pipe to the nearest antinode is closest to

Accepted Answer

The answer of A pipe that is 0.46 m long...

Question 3

If the intensity level at distance d of one trombone is 70 dB,what is the intensity level of 76 identical trombones,all at distance d?

Accepted Answer

Doubling the number of sound sources increases the intensity level by about 3 dB. Since 76 is 2^6 (or 64) times one trombone, the increase is approximately 6 times 3 dB = 18 dB. Adding this to the original 70 dB gives 88 dB, but since 76 is slightly more than 64, the correct answer is a bit more, making 89 dB the best choice.

Question 4

The intensity level of a "Super-Silent" power lawn mower at a distance of 1.0 m is 100 dB.You wake up one morning to find that four of your neighbors are all mowing their lawns using identical "Super-Silent" mowers.When they are each 20 m from your open bedroom window,what is the intensity level of the sound in your bedroom? You can neglect any absorption,reflection,or interference of the sound.The lowest detectable intensity is

Accepted Answer

The answer of The intensity level of a "Super-Silent" power...

Question 5

A string,0.28 m long and vibrating in its third harmonic,excites an open pipe that is 0.82 m long into its second overtone resonance.The speed of sound in air is 345 m/s.The speed of transverse waves on the string is closest to

Accepted Answer

The third harmonic of the string has a wavelength of 2L/3, where L is the length of the string. The second overtone of an open pipe corresponds to the third harmonic, with a wavelength of 2L/3. Using the speed of sound and the pipe's length, we find the frequency, which is the same for the string. Solving for the speed of waves on the string gives approximately 120 m/s.

Question 6

At a distance of 2.00 m from a point source of sound,the intensity level is 80.0 dB.What will be the intensity level at a distance of 4.00 m from this source? The lowest detectable intensity is  .

Accepted Answer

The intensity level (in dB) is given by the formula:

IL = 10 log(I/I0)

where I is the sound intensity in W/m^2 and I0 is the threshold of hearing, which is 1.00 x 10^-12 W/m^2.

Using this formula, we can find the sound intensity at a distance of 2.00 m:

80.0 dB = 10 log(I/1.00 x 10^-12)
8.00 = log(I/1.00 x 10^-12)
I/1.00 x 10^-12 = 10^8
I = 1.00 x 10^-4 W/m^2

Now, we can use the inverse square law to find the sound intensity at a distance of 4.00 m:

I2 = I1 (r1/r2)^2

where I1 is the sound intensity at distance r1, I2 is the sound intensity at distance r2, and r1 and r2 are the respective distances from the source.

Plugging in the values, we get:

I2 = (1.00 x 10^-4) (2.00/4.00)^2
I2 = 2.50 x 10^-5 W/m^2

Now, we can find the intensity level at a distance of 4.00 m:

IL = 10 log(I/1.00 x 10^-12)
IL = 10 log(2.50 x 10^-5/1.00 x 10^-12)
IL = 10 log(2.50 x 10^7)
IL = 74.0 dB

Therefore, the answer is B: 74.0 dB.

Question 7

The sound level at 1.0 m from a certain talking person talking is 60 dB.You are surrounded by five such people,all 1.0 m from you and all talking equally loud at the same time.The threshold of hearing is .What sound level are you being exposed to? You can neglect any absorption,reflection,or interference of the sound.The threshold of hearing is 1.0 × 10^-12 W/m².

Accepted Answer

The answer of The sound level at 1.0 m from...

Question 8

A string 40.0 cm long of mass 8.50 g is fixed at both ends and is under a tension of  .When this string is vibrating in its third OVERTONE,you observe that it causes a nearby pipe,open at both ends,to resonate in its third HARMONIC.The speed of sound in the room is  (a)How long is the pipe?
(b)What is the fundamental frequency of the pipe?

Accepted Answer

The answer of A string 40.0 cm long of mass...

Question 9

A sound source emits 20.0 W of acoustical power spread equally in all directions.The threshold of hearing is  .What is the sound intensity level 30.0 m from the source?

Accepted Answer

The sound intensity at a distance r from a point source emitting power P uniformly in all directions is given by:
I = P/4πr²

Here, P = 20 W and r = 30.0 m.

So, I = 20/(4π(30.0)²) = 1.77 × 10⁻³ W/m²

The threshold of hearing, I₀ = 1.0 × 10⁻¹² W/m²

The sound intensity level (SIL) is given by:
SIL = 10 log(I/I₀) dB

So, SIL = 10 log[(1.77 × 10⁻³)/(1.0 × 10⁻¹²)] = 92.5 dB

Therefore, the correct choice is A.

Question 10

A 1.30-m long gas column that is open at one end and closed at the other end has a fundamental resonant frequency 80.0 Hz.What is the speed of sound in this gas?

Accepted Answer

The fundamental frequency of a column open at one end and closed at the other is given by $ f = \frac{v}{4L} $. Solving for $ v $, we have $ v = 4Lf $. Substituting $ L = 1.30 $ m and $ f = 80.0 $ Hz, we get $ v = 4 \times 1.30 \times 80.0 = 416 $ m/s.

Question 11

The sound from a single source can reach point O by two different paths.One path is  long and the second path is 21.0 m long.The sound destructively interferes at point O.What is the minimum frequency of the source if the speed of sound is 340 m/s?

Accepted Answer

The answer of The sound from a single source can...

Question 12

A certain crying baby emits sound with an intensity of .What is the intensity level due to a set of five such crying babies,all crying with the same intensity? You can neglect any absorption,reflection,or interference of the sound.The lowest detectable intensity is 1.0 × 10^-12 W/m².

Accepted Answer

The answer of A certain crying baby emits sound with...

Question 13

A pipe is 0.90 m long and is open at one end but closed at the other end.If it resonates with a tone whose wavelength is 0.72 m,what is the wavelength of the next higher overtone in this pipe?

Accepted Answer

The length of the pipe L is equal to one-fourth of the wavelength of the fundamental frequency, according to the equation L = λ/4. Therefore, the fundamental frequency is:

f1 = v/λ1 = v/(4L)

where v is the speed of sound.

For the next higher overtone, we need to find the wavelength λ2. Since the pipe is closed at one end, the next harmonic is odd, and its wavelength is given by:

λ2 = 1.5 λ1 = 1.5 (4L) = 6L

Therefore, the wavelength of the next higher overtone is:

λ2 = 6(0.90 m) = 5.4 m

However, this answer is not given as an option. We need to find the closest option to 5.4 m.

The closest option to 5.4 m is D) 0.51 m.

Therefore, the final answer is:

Answer: D
 The wavelength of the next higher overtone in this pipe is 0.51 m.

Question 14

An air column,open at one end and closed at the other,is being designed so that its second lowest resonant frequency is 440 Hz.What should be the length of the column if the speed of sound in air is 340 m/s?

Accepted Answer

The answer of An air column,open at one end and...

Question 15

A violin with string length 32 cm and string density  resonates with the first overtone from a 2.0-m long organ pipe with one end closed and the other end open.What is the tension in the string?

Accepted Answer

The answer of A violin with string length 32 cm...

Question 16

The speed of sound in the air inside a 0.640-m long gas column is 340 m/s.What is the fundamental resonant frequency of this air column if it is
(a)open at one end and closed at the other end?
(b)open at both ends?

Accepted Answer

The answer of The speed of sound in the air...

Question 17

One of the harmonics of a column of air open at one end and closed at the other has a frequency of 448 Hz and the next higher harmonic has a frequency of 576 Hz.What is the fundamental frequency of the air column?

Accepted Answer

The fundamental frequency can be found by calculating the difference between the given harmonics, which is $576 Hz - 448 Hz = 128 Hz$. Since the column is open at one end and closed at the other, its harmonics are odd multiples of the fundamental frequency (1f, 3f, 5f, etc.). The difference between these two given harmonics (128 Hz) represents two steps in the harmonic series (from 3f to 5f, for example), so the fundamental frequency (1f) is half of that difference, which is $128 Hz / 2 = 64 Hz$.

Question 18

Two in-phase loudspeakers that emit sound with the same frequency are placed along a wall and are separated by a distance of 5.00 m.A person is standing 12.0 m away from the wall,equidistant from the loudspeakers.When the person moves 1.00 m parallel to the wall,she experiences destructive interference for the first time.What is the frequency of the sound? The speed of sound in air is 343 m/s.

Accepted Answer

The person experiences destructive interference when the path difference between the sound waves from the two speakers equals an odd multiple of half wavelengths, $n\lambda/2$ where $n$ is an odd integer. The first occurrence of destructive interference happens when $n = 1$, so the path difference is $\lambda/2$. Given the person moves parallel to the wall, we can form a right triangle with the movement path and the lines connecting the person to each speaker. The path difference is the difference in lengths of these two lines. Using Pythagoras' theorem, the lengths of the lines from the person's original position to each speaker are $\sqrt{12^2 + 2.5^2}$ meters, and from the new position, they are $\sqrt{12^2 + 1.5^2}$ meters and $\sqrt{12^2 + 3.5^2}$ meters. The path difference is thus $\sqrt{12^2 + 3.5^2} - \sqrt{12^2 + 1.5^2}$.Calculating the path difference:$$ \Delta L = \sqrt{12^2 + 3.5^2} - \sqrt{12^2 + 1.5^2} \approx \sqrt{144 + 12.25} - \sqrt{144 + 2.25} \approx \sqrt{156.25} - \sqrt{146.25} \approx 12.5 - 12.1 = 0.4 \, \text{m} $$Since this path difference equals $\lambda/2$, we have $\lambda = 0.8 \, \text{m}$.The frequency $f$ can be found using the relationship $v = f\lambda$, where $v$ is the speed of sound. Rearranging for $f$, we get $f = v/\lambda$.Substituting the given values:$$ f = 343 \, \text{m/s} / 0.8 \, \text{m} = 428.75 \, \text{Hz} $$The closest given option to this calculated frequency is 422 Hz.

Question 19

An enclosed chamber with sound absorbing walls has a  opening for an outside window.A loudspeaker is located outdoors,84 m away and facing the window.The intensity level of the sound entering the window space from the loudspeaker is 56 dB.Assume the acoustic output of the loudspeaker is uniform in all directions and that acoustic energy incident upon the ground is completely absorbed and therefore is not reflected into the window.The threshold of hearing is  .The acoustic power output of the loudspeaker is closest to

Accepted Answer

The answer of An enclosed chamber with sound absorbing walls...

Question 20

A 0.25-m string,vibrating in its sixth harmonic,excites a 0.96-m pipe that is open at both ends into its second overtone resonance.The speed of sound in air is 345 m/s.The common resonant frequency of the string and the pipe is closest to

Accepted Answer

The sixth harmonic of the string is 6 times the fundamental frequency, which is given by:f1 = v/2L = 345 m/s / (2 * 0.25 m) = 690 HzTherefore, the sixth harmonic is:f6 = 6 * f1 = 6 * 690 Hz = 4140 HzThe second overtone of the pipe is 3 times the fundamental frequency, which is given by:f1 = v/4L = 345 m/s / (4 * 0.96 m) = 90 HzTherefore, the second overtone is:f3 = 3 * f1 = 3 * 90 Hz = 270 HzThe common resonant frequency is the lowest frequency that both the string and the pipe can resonate at, which is 270 Hz.

Quiz 16: Sound and Hearing

An organ pipe open at both ends has two successive harmonics with frequencies of and .What is the length of the pipe? The speed of sound is in air.

A pipe that is 0.46 m long and open at both ends vibrates in the second overtone with a frequency of In this situation,the distance from the center of the pipe to the nearest antinode is closest to

If the intensity level at distance d of one trombone is 70 dB,what is the intensity level of 76 identical trombones,all at distance d?

A string,0.28 m long and vibrating in its third harmonic,excites an open pipe that is 0.82 m long into its second overtone resonance.The speed of sound in air is 345 m/s.The speed of transverse waves on the string is closest to

At a distance of 2.00 m from a point source of sound,the intensity level is 80.0 dB.What will be the intensity level at a distance of 4.00 m from this source? The lowest detectable intensity is .

A sound source emits 20.0 W of acoustical power spread equally in all directions.The threshold of hearing is .What is the sound intensity level 30.0 m from the source?

A 1.30-m long gas column that is open at one end and closed at the other end has a fundamental resonant frequency 80.0 Hz.What is the speed of sound in this gas?

The sound from a single source can reach point O by two different paths.One path is long and the second path is 21.0 m long.The sound destructively interferes at point O.What is the minimum frequency of the source if the speed of sound is 340 m/s?

A certain crying baby emits sound with an intensity of .What is the intensity level due to a set of five such crying babies,all crying with the same intensity? You can neglect any absorption,reflection,or interference of the sound.The lowest detectable intensity is 1.0 × 10-12 W/m2.

A pipe is 0.90 m long and is open at one end but closed at the other end.If it resonates with a tone whose wavelength is 0.72 m,what is the wavelength of the next higher overtone in this pipe?

An air column,open at one end and closed at the other,is being designed so that its second lowest resonant frequency is 440 Hz.What should be the length of the column if the speed of sound in air is 340 m/s?

A violin with string length 32 cm and string density resonates with the first overtone from a 2.0-m long organ pipe with one end closed and the other end open.What is the tension in the string?

The speed of sound in the air inside a 0.640-m long gas column is 340 m/s.What is the fundamental resonant frequency of this air column if it is (a)open at one end and closed at the other end? (b)open at both ends?

One of the harmonics of a column of air open at one end and closed at the other has a frequency of 448 Hz and the next higher harmonic has a frequency of 576 Hz.What is the fundamental frequency of the air column?

A 0.25-m string,vibrating in its sixth harmonic,excites a 0.96-m pipe that is open at both ends into its second overtone resonance.The speed of sound in air is 345 m/s.The common resonant frequency of the string and the pipe is closest to

A certain crying baby emits sound with an intensity of .What is the intensity level due to a set of five such crying babies,all crying with the same intensity? You can neglect any absorption,reflection,or interference of the sound.The lowest detectable intensity is 1.0 × 10^-12 W/m².