Question 1

If two adjacent frequencies of an organ pipe closed at one end are 385 Hz and 578 Hz,what is the length of the organ pipe? (vsound = 340 m/s)

Accepted Answer

A) 0.44 m 
B) 0.59 m 
C) 1.4 m 
D) 0.88 m 
E) 1.8 m 
A) 0.44 m 
B) 0.59 m 
C) 1.4 m 
D) 0.88 m 
E) 1.8 m

Question 2

Material 1 has Young's modulus Y1 and density ρ​1,and material 2 has Young's modulus Y​2 and density ρ2.If Y1 is 30% more than Y​2 and ρ​1 is 30% less than ρ2,which material has the higher speed of sound and how much higher is it?

Accepted Answer

A) Material 1 has a speed of sound more than 35% higher than material 2. 
B) Material 1 has a speed of sound 30% higher than material 2. 
C) Material 2 has a speed of sound more than 80% higher than material 1. 
D) Material 2 has a speed of sound 30% higher than material 1. 
A) Material 1 has a speed of sound more than 35% higher than material 2. 
B) Material 1 has a speed of sound 30% higher than material 2. 
C) Material 2 has a speed of sound more than 80% higher than material 1. 
D) Material 2 has a speed of sound 30% higher than material 1.

Question 3

A train station bell gives off a fundamental tone of 500 Hz as the train approaches the station at a speed of 30.0 m/s.If the speed of sound in air is 339 m/s,what will be the apparent frequency of the bell to an observer riding the train?

Accepted Answer

A) 456 Hz 
B) 544 Hz 
C) 250 Hz 
D) 530 Hz 
E) 339 Hz 
A) 456 Hz 
B) 544 Hz 
C) 250 Hz 
D) 530 Hz 
E) 339 Hz

Question 4

Two loudspeakers are placed next to each other and driven by the same source at 515 Hz.A listener is positioned in front of the two speakers and on the line separating them,thus creating a constructive interference at the listener's ear.What minimum distance would one of the speakers be moved back away from the listener to produce destructive interference at the listener's ear? (The speed of sound = 340 m/s. )

Accepted Answer

A) 1.5 m 
B) 0.66 m 
C) 0.33 m 
D) 0.17 m 
E) 3.0 m 
A) 1.5 m 
B) 0.66 m 
C) 0.33 m 
D) 0.17 m 
E) 3.0 m

Question 5

While standing at a crosswalk,you hear a frequency of 600 Hz from an approaching police car.After the police car passes,its frequency is 400 Hz.What is the speed of the police car? (speed of sound = 340 m/s)

Accepted Answer

A) 34.0 m/s 
B) 60.0 m/s 
C) 66.3 m/s 
D) 68.0 m/s 
E) 199 m/s 
A) 34.0 m/s 
B) 60.0 m/s 
C) 66.3 m/s 
D) 68.0 m/s 
E) 199 m/s

Question 6

The lower A on a piano has a frequency of 30.0 Hz.If the tension in the 2.00-m-long string is 316 N and one-half wavelength occupies the string,what is the mass of the string?

Accepted Answer

A) 61.4 g 
B) 21.9 g 
C) 17.6 g 
D) 43.9 g 
E) 91.1 g 
A) 61.4 g 
B) 21.9 g 
C) 17.6 g 
D) 43.9 g 
E) 91.1 g

Question 7

If I0 = 10−12 W/m2 is the threshold of hearing,a sound with intensity I1 = 10−11 W/m2 will give a certain decibel level.Suppose a new sound has an intensity I2 = 2I12/I0.What is the new decibel level?

Accepted Answer

A) 2.3 dB 
B) 23 dB 
C) 100 dB 
D) it will square the decibel level 
E) 1.0 dB 
A) 2.3 dB 
B) 23 dB 
C) 100 dB 
D) it will square the decibel level 
E) 1.0 dB

Question 8

For a standing wave on a string the wavelength must equal

Accepted Answer

A) the distance between adjacent nodes. 
B) the distance between adjacent antinodes. 
C) twice the distance between adjacent nodes. 
D) the distance between supports. 
A) the distance between adjacent nodes. 
B) the distance between adjacent antinodes. 
C) twice the distance between adjacent nodes. 
D) the distance between supports.

Question 9

A source of sound has an intensity I​1 and when its sound level is measured at a fixed distance the value found is 70 dB.The source then has its intensity increased to I​2 and when its sound level is measured at the same distance the value found is 96 dB.What is the ratio ​I​2/​I​1?

Accepted Answer

A) 26 
B) 400 
C) 600 
D) 14 
A) 26 
B) 400 
C) 600 
D) 14

Question 10

When the standing wave pattern in a pipe is NANA,the pipe has which of the following set of properties? (N stands for node,A for antinode. )

Accepted Answer

A) It is open at both ends. 
B) It is closed at both ends. 
C) It is open at one end and closed at the other end. 
D) Any of the above could be true. 
A) It is open at both ends. 
B) It is closed at both ends. 
C) It is open at one end and closed at the other end. 
D) Any of the above could be true.

Question 11

What is the intensity of a sound with a measured intensity level of 85 dB? (I0 = 10−12 W/m2)

Accepted Answer

A) 1.3E-6 W/m2 
B) 3.2E-4 W/m2 
C) 8.5E-6 W/m2 
D) 2.0E-3 W/m2 
E) ​8.5E-3 W/m2 
A) 1.3E-6 W/m2 
B) 3.2E-4 W/m2 
C) 8.5E-6 W/m2 
D) 2.0E-3 W/m2 
E) ​8.5E-3 W/m2

Question 12

A C note (f = 256 Hz)is sounded on a piano.If the length of the piano wire is 1.8 m and its mass density is 2.2 g/m,what is the tension in the wire?

Accepted Answer

A) 6.4E+1 N 
B) 1.4E+2 N 
C) 1.9E+3 N 
D) 1.1E+3 N 
E) 5.6E+2 N 
A) 6.4E+1 N 
B) 1.4E+2 N 
C) 1.9E+3 N 
D) 1.1E+3 N 
E) 5.6E+2 N

Question 13

Which of the following ranges corresponds to the shortest wavelengths?

Accepted Answer

A) infrasonic 
B) audible 
C) ultrasonic 
D) All have the same wavelengths. 
A) infrasonic 
B) audible 
C) ultrasonic 
D) All have the same wavelengths.

Question 14

The term "timbre" refers to which of the following?

Accepted Answer

A) Any musical instrument made primarily of wood. 
B) The quality of sound from instruments due to the mixture of harmonics. 
C) Instruments that have valves. 
D) An instrument made in France. 
A) Any musical instrument made primarily of wood. 
B) The quality of sound from instruments due to the mixture of harmonics. 
C) Instruments that have valves. 
D) An instrument made in France.

Question 15

The Doppler shift of ultrasonic waves can measure the speed of blood in an artery.If the frequency of the stationary source is 95.0 kHz and the reflected sound has a Doppler shift of 210 Hz,what is the blood flow speed? (The speed of sound inside the body is 1 500 m/s. )

Accepted Answer

A) 1.0 m/s 
B) 1.7 m/s 
C) 3.3 m/s 
D) 3.9 m/s 
E) 6.5 m/s 
A) 1.0 m/s 
B) 1.7 m/s 
C) 3.3 m/s 
D) 3.9 m/s 
E) 6.5 m/s

Question 16

A speaker designed to emit spherical sound waves is producing a sound intensity of 8 W/m2 at a distance of 1 m from the speaker.What would be the intensity of this sound at a distance of 2 m from the speaker?

Accepted Answer

A)    W/m2 
B) 4 W/m2 
C)    W/m2 ​ 
D) 2 W/m2 
A)    W/m2 
B) 4 W/m2 
C)    W/m2 ​ 
D) 2 W/m2

Question 17

A 550-Hz whistle is moved toward a listener at a speed of 25.0 m/s.At the same time,the listener moves at a speed of 35.0 m/s in a direction away from the whistle.What is the apparent frequency heard by the listener? (The speed of sound is 340 m/s. )

Accepted Answer

A) 510 Hz 
B) 533 Hz 
C) 655 Hz 
D) 460 Hz 
E) 594 Hz 
A) 510 Hz 
B) 533 Hz 
C) 655 Hz 
D) 460 Hz 
E) 594 Hz

Question 18

If I quadruple the mass per unit length of guitar string,its natural frequency changes by what factor?

Accepted Answer

A)    
B) 1 
C)    
D) 4 
E) 42 
A)    
B) 1 
C)    
D) 4 
E) 42

Question 19

Standing-wave vibrations are set up in a crystal wine glass with four nodes and four antinodes equally spaced around the 2.80-cm radius of the rim.If the resonant frequency of the glass is 8.50 kHz,what is the speed of the transverse waves moving around the glass?

Accepted Answer

A) 1 500 m/s 
B) 748 m/s 
C) 374 m/s 
D) 238 m/s 
A) 1 500 m/s 
B) 748 m/s 
C) 374 m/s 
D) 238 m/s

Question 20

Material 1 has Young's modulus Y1 and density ρ1,material 2 has Young's modulus Y2 and density ρ2,and material 3 has Young's modulus Y3 and density ρ​3.If Y1 > Y2 > Y3 and if ρ1  < ρ​3,which material has the highest speed of sound?

Accepted Answer

A) material 1 
B) material 2 
C) material 3 
D) They could all have equal speeds of sound. 
A) material 1 
B) material 2 
C) material 3 
D) They could all have equal speeds of sound.

Exam 14: Sound

If two adjacent frequencies of an organ pipe closed at one end are 385 Hz and 578 Hz,what is the length of the organ pipe? (vsound = 340 m/s)

Material 1 has Young's modulus Y1 and density ρ​1,and material 2 has Young's modulus Y​2 and density ρ2.If Y1 is 30% more than Y​2 and ρ​1 is 30% less than ρ2,which material has the higher speed of sound and how much higher is it?

A train station bell gives off a fundamental tone of 500 Hz as the train approaches the station at a speed of 30.0 m/s.If the speed of sound in air is 339 m/s,what will be the apparent frequency of the bell to an observer riding the train?

While standing at a crosswalk,you hear a frequency of 600 Hz from an approaching police car.After the police car passes,its frequency is 400 Hz.What is the speed of the police car? (speed of sound = 340 m/s)

The lower A on a piano has a frequency of 30.0 Hz.If the tension in the 2.00-m-long string is 316 N and one-half wavelength occupies the string,what is the mass of the string?

If I0 = 10−12 W/m2 is the threshold of hearing,a sound with intensity I1 = 10−11 W/m2 will give a certain decibel level.Suppose a new sound has an intensity I2 = 2I12/I0.What is the new decibel level?

For a standing wave on a string the wavelength must equal

A source of sound has an intensity I​1 and when its sound level is measured at a fixed distance the value found is 70 dB.The source then has its intensity increased to I​2 and when its sound level is measured at the same distance the value found is 96 dB.What is the ratio ​I​2/​I​1?

When the standing wave pattern in a pipe is NANA,the pipe has which of the following set of properties? (N stands for node,A for antinode. )

What is the intensity of a sound with a measured intensity level of 85 dB? (I0 = 10−12 W/m2)

A C note (f = 256 Hz)is sounded on a piano.If the length of the piano wire is 1.8 m and its mass density is 2.2 g/m,what is the tension in the wire?

Which of the following ranges corresponds to the shortest wavelengths?

The term "timbre" refers to which of the following?

The Doppler shift of ultrasonic waves can measure the speed of blood in an artery.If the frequency of the stationary source is 95.0 kHz and the reflected sound has a Doppler shift of 210 Hz,what is the blood flow speed? (The speed of sound inside the body is 1 500 m/s. )

A speaker designed to emit spherical sound waves is producing a sound intensity of 8 W/m2 at a distance of 1 m from the speaker.What would be the intensity of this sound at a distance of 2 m from the speaker?

A 550-Hz whistle is moved toward a listener at a speed of 25.0 m/s.At the same time,the listener moves at a speed of 35.0 m/s in a direction away from the whistle.What is the apparent frequency heard by the listener? (The speed of sound is 340 m/s. )

If I quadruple the mass per unit length of guitar string,its natural frequency changes by what factor?

Standing-wave vibrations are set up in a crystal wine glass with four nodes and four antinodes equally spaced around the 2.80-cm radius of the rim.If the resonant frequency of the glass is 8.50 kHz,what is the speed of the transverse waves moving around the glass?

Material 1 has Young's modulus Y1 and density ρ1,material 2 has Young's modulus Y2 and density ρ2,and material 3 has Young's modulus Y3 and density ρ​3.If Y1 > Y2 > Y3 and if ρ1 < ρ2 < ρ​3,which material has the highest speed of sound?

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Filters

If two adjacent frequencies of an organ pipe closed at one end are 385 Hz and 578 Hz,what is the length of the organ pipe? (v_sound = 340 m/s)

Material 1 has Young's modulus Y₁ and density ρ₁,and material 2 has Young's modulus Y₂and density ρ₂.If Y₁ is 30% more than Y₂ and ρ₁ is 30% less than ρ₂,which material has the higher speed of sound and how much higher is it?

If I₀ = 10−¹² W/m² is the threshold of hearing,a sound with intensity I₁ = 10−¹¹ W/m² will give a certain decibel level.Suppose a new sound has an intensity I₂ = 2I₁²/I₀.What is the new decibel level?

A source of sound has an intensity I₁ and when its sound level is measured at a fixed distance the value found is 70 dB.The source then has its intensity increased to I₂ and when its sound level is measured at the same distance the value found is 96 dB.What is the ratio I₂/I₁?

What is the intensity of a sound with a measured intensity level of 85 dB? (I₀ = 10−¹² W/m²)

A speaker designed to emit spherical sound waves is producing a sound intensity of 8 W/m² at a distance of 1 m from the speaker.What would be the intensity of this sound at a distance of 2 m from the speaker?

Material 1 has Young's modulus Y1 and density ρ1,material 2 has Young's modulus Y₂ and density ρ₂,and material 3 has Young's modulus Y3and density ρ₃.If Y1> Y₂ > Y3and if ρ1< ρ2< ρ3,which material has the highest speed of sound?