Question 1

If the distance between a point sound source and a dB detector is increased by a factor of 5,what will be the reduction in intensity level?

Accepted Answer

A)  14 dB 
B)  0.04 dB 
C)  5 dB 
D)  26 dB 
E)  ​0.20 dB 
A)  14 dB 
B)  0.04 dB 
C)  5 dB 
D)  26 dB 
E)  ​0.20 dB

Question 2

Two vibrating tuning forks,held side by side,will create a beat frequency of what value if the individual frequencies of the two forks are 348 Hz and 331 Hz,respectively?

Accepted Answer

A)  679 Hz 
B)  339.5 Hz 
C)  314 Hz 
D)  17 Hz 
E)  ​331 Hz 
A)  679 Hz 
B)  339.5 Hz 
C)  314 Hz 
D)  17 Hz 
E)  ​331 Hz

Question 3

A 95-m-long high-voltage cable is suspended between two towers.The mass of the 95-m cable is 125 kg.If the tension in the cable is 27,500 N,what is the lowest frequency at which this cable can oscillate?

Accepted Answer

A)  0.76 Hz 
B)  1 Hz 
C)  1.52 Hz 
D)  2 Hz 
E)  ​3.04 Hz 
A)  0.76 Hz 
B)  1 Hz 
C)  1.52 Hz 
D)  2 Hz 
E)  ​3.04 Hz

Question 4

If two adjacent frequencies of an organ pipe closed at one end are 510 Hz and 635 Hz,what is the length of the organ pipe? (vsound = 340 m/s)

Accepted Answer

A)  0.7 m 
B)  0.9 m 
C)  1.2 m 
D)  1.4 m 
E)  ​2.7 m 
A)  0.7 m 
B)  0.9 m 
C)  1.2 m 
D)  1.4 m 
E)  ​2.7 m

Question 5

While standing at a crosswalk,you hear a frequency of 590 Hz from an approaching police car.After the police car passes,its frequency is 440Hz.What is the speed of the police car? (speed of sound = 340 m/s)

Accepted Answer

A)  24.8 m/s 
B)  38.3 m/s 
C)  44.7 m/s 
D)  49.5 m/s 
E)  ​148.7 m/s 
A)  24.8 m/s 
B)  38.3 m/s 
C)  44.7 m/s 
D)  49.5 m/s 
E)  ​148.7 m/s

Question 6

Two loudspeakers are placed next to each other and driven by the same source at 460 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)  1.35 m 
B)  0.74 m 
C)  0.37 m 
D)  0.18 m 
E)  ​2.71 m 
A)  1.35 m 
B)  0.74 m 
C)  0.37 m 
D)  0.18 m 
E)  ​2.71 m

Question 7

A bat,flying at 6 m/s toward a wall,emits a chirp at 48 kHz.If the wall reflects this sound pulse,what is the frequency of the echo received by the bat? (vsound = 340 m/s)

Accepted Answer

A)  49.7 kHz 
B)  48.9 kHz 
C)  48.0 kHz 
D)  47.2 kHz 
E)  ​56.7 kHz 
A)  49.7 kHz 
B)  48.9 kHz 
C)  48.0 kHz 
D)  47.2 kHz 
E)  ​56.7 kHz

Question 8

Two loudspeakers are placed side by side and driven by the same source at 490 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.If one of the speakers is gradually pushed toward the listener,how far must it be moved to repeat the condition of constructive interference at the listener's ear? (The speed of sound = 340 m/s. )

Accepted Answer

A)  1.44 m 
B)  0.69 m 
C)  0.35 m 
D)  0.17 m 
E)  ​2.88 m 
A)  1.44 m 
B)  0.69 m 
C)  0.35 m 
D)  0.17 m 
E)  ​2.88 m

Question 9

A sound source of frequency 1,090 Hz moves at 40 m/s toward a listener who is at rest.What is the apparent frequency heard by the listener? (speed of sound = 340 m/s)

Accepted Answer

A)  1,218 Hz 
B)  962 Hz 
C)  980 Hz 
D)  1,240 Hz 
E)  ​861 Hz 
A)  1,218 Hz 
B)  962 Hz 
C)  980 Hz 
D)  1,240 Hz 
E)  ​861 Hz

Question 10

A relatively new medical device that uses ultrasonics is referred to by the acronym CUSA.What does the letter A stand for?

Accepted Answer

A)  aspirator 
B)  accumulator 
C)  array 
D)  audible 
A)  aspirator 
B)  accumulator 
C)  array 
D)  audible

Question 11

A sound wave coming from a tuba has a wavelength of 1.1 m and travels to your ears at a speed of 220 m/s.What is the frequency of the sound you hear?

Accepted Answer

A)  242 Hz 
B)  1/242 Hz 
C)  200 Hz 
D)  1/200 Hz 
E)  ​218.9 Hz 
A)  242 Hz 
B)  1/242 Hz 
C)  200 Hz 
D)  1/200 Hz 
E)  ​218.9 Hz

Question 12

I stretch a rubber band and "plunk" it to make it vibrate in its fundamental frequency.I then stretch it to twice its length and make it vibrate in the fundamental frequency once again.The rubber band is made so that doubling its length doubles the tension and reduces the mass per unit length by a factor of 2.The new frequency will be related to the old by a factor of:

Accepted Answer

A)  1. 
B)  1.4. 
C)  2. 
D)  4. 
E)  ​1/2 
A)  1. 
B)  1.4. 
C)  2. 
D)  4. 
E)  ​1/2

Question 13

The density of a certain metal solid is 7 × 103 kg/m3,and its Young's modulus is 13 × 1010 N/m2.What is the speed of sound in this metal?

Accepted Answer

A)  1.4 × 107 m/s 
B)  4,400 m/s 
C)  4,300 m/s 
D)  4,000 m/s 
E)  ​1.4 × 103 m/s 
A)  1.4 × 107 m/s 
B)  4,400 m/s 
C)  4,300 m/s 
D)  4,000 m/s 
E)  ​1.4 × 103 m/s

Question 14

A standing wave is set up in a 5-m string fixed at both ends.The string vibrates in 7 distinct segments when driven by a 110-Hz source.In how many distinct standing wave segments will the string vibrate if the tension is increased by a factor of 5?

Accepted Answer

A)  2 
B)  18 
C)  35 
D)  ​79 
E)  ​No standing wave pattern occurs. 
A)  2 
B)  18 
C)  35 
D)  ​79 
E)  ​No standing wave pattern occurs.

Question 15

Comparing the speed of sound in liquids,gases,and solids,the speed of sound is usually lowest in ____ and highest in ____.

Accepted Answer

A)  solids,liquids 
B)  gases,liquids 
C)  liquids,solids 
D)  gases,solids 
A)  solids,liquids 
B)  gases,liquids 
C)  liquids,solids 
D)  gases,solids

Question 16

A series of ocean waves,3 m between crests,move past at 2 waves/s.Find their speed.

Accepted Answer

A)  1.50 m/s 
B)  3 m/s 
C)  5 m/s 
D)  6 m/s 
E)  ​1 m/s 
A)  1.50 m/s 
B)  3 m/s 
C)  5 m/s 
D)  6 m/s 
E)  ​1 m/s

Question 17

Assuming that the wave speed varies little when sound waves are traveling though a material that suddenly changes density by 8%,what percentage of the incident wave intensity is reflected?

Accepted Answer

A)  < 1% 
B)  7% 
C)  8% 
D)  20% 
E)  ​25% 
A)  < 1% 
B)  7% 
C)  8% 
D)  20% 
E)  ​25%

Question 18

Two cars,one in front of the other,are traveling down the highway at 44 m/s.The car behind sounds its horn,which has a frequency of 530 Hz.What is the frequency heard by the driver of the lead car? (vsound = 340 m/s)

Accepted Answer

A)  409 Hz 
B)  688 Hz 
C)  469 Hz 
D)  530 Hz 
E)  ​609 Hz 
A)  409 Hz 
B)  688 Hz 
C)  469 Hz 
D)  530 Hz 
E)  ​609 Hz

Question 19

What is the fourth overtone frequency for an organ pipe 3 m in length,closed at one end? The speed of sound in air is 340 m/s.

Accepted Answer

A)  28 Hz 
B)  57 Hz 
C)  255 Hz 
D)  1,020 Hz 
E)  ​2,040 Hz 
A)  28 Hz 
B)  57 Hz 
C)  255 Hz 
D)  1,020 Hz 
E)  ​2,040 Hz

Question 20

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

Accepted Answer

A)  0.50 
B)  1 
C)  2.00 
D)  4 
E)  ​16 
A)  0.50 
B)  1 
C)  2.00 
D)  4 
E)  ​16

Exam 14: Sound

If the distance between a point sound source and a dB detector is increased by a factor of 5,what will be the reduction in intensity level?

Two vibrating tuning forks,held side by side,will create a beat frequency of what value if the individual frequencies of the two forks are 348 Hz and 331 Hz,respectively?

A 95-m-long high-voltage cable is suspended between two towers.The mass of the 95-m cable is 125 kg.If the tension in the cable is 27,500 N,what is the lowest frequency at which this cable can oscillate?

If two adjacent frequencies of an organ pipe closed at one end are 510 Hz and 635 Hz,what is the length of the organ pipe? (vsound = 340 m/s)

While standing at a crosswalk,you hear a frequency of 590 Hz from an approaching police car.After the police car passes,its frequency is 440Hz.What is the speed of the police car? (speed of sound = 340 m/s)

A bat,flying at 6 m/s toward a wall,emits a chirp at 48 kHz.If the wall reflects this sound pulse,what is the frequency of the echo received by the bat? (vsound = 340 m/s)

A sound source of frequency 1,090 Hz moves at 40 m/s toward a listener who is at rest.What is the apparent frequency heard by the listener? (speed of sound = 340 m/s)

A relatively new medical device that uses ultrasonics is referred to by the acronym CUSA.What does the letter A stand for?

A sound wave coming from a tuba has a wavelength of 1.1 m and travels to your ears at a speed of 220 m/s.What is the frequency of the sound you hear?

The density of a certain metal solid is 7 × 103 kg/m3,and its Young's modulus is 13 × 1010 N/m2.What is the speed of sound in this metal?

A standing wave is set up in a 5-m string fixed at both ends.The string vibrates in 7 distinct segments when driven by a 110-Hz source.In how many distinct standing wave segments will the string vibrate if the tension is increased by a factor of 5?

Comparing the speed of sound in liquids,gases,and solids,the speed of sound is usually lowest in ____ and highest in ____.

A series of ocean waves,3 m between crests,move past at 2 waves/s.Find their speed.

Assuming that the wave speed varies little when sound waves are traveling though a material that suddenly changes density by 8%,what percentage of the incident wave intensity is reflected?

Two cars,one in front of the other,are traveling down the highway at 44 m/s.The car behind sounds its horn,which has a frequency of 530 Hz.What is the frequency heard by the driver of the lead car? (vsound = 340 m/s)

What is the fourth overtone frequency for an organ pipe 3 m in length,closed at one end? The speed of sound in air is 340 m/s.

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

Introduction

Introduction: Part A

Motion in One Dimension

Motion in One Dimension: Part A

Vectors and Two-Dimensional Motion

Vectors and Two-Dimensional Motion: Part A

The Laws of Motion

The Laws of Motion: Part A

Energy

Energy: Part A

Momentum and Collisions

Momentum and Collisions: Part A

Rotational Motion and the Law of Gravity

Rotational Motion and the Law of Gravity: Part A

Rotational Equilibrium and Rotational Dynamics

Rotational Equilibrium and Rotational Dynamics: Part A

Solids and Fluids

Solids and Fluids: Part A

Thermal Physics

Thermal Physics: Part A

Energy in Thermal Processes Heat and Internal Energy

Energy in Thermal Processes Heat and Internal Energy: Part A

The Laws of Thermodynamics Work in Thermodynamic Processes

The Laws of Thermodynamics Work in Thermodynamic Processes: Part A

Vibrations and Waves

Vibrations and Waves: Part A

Sound: Part A

Electric Forces and Electric Fields

Electric Forces and Electric Fields: Part A

Electrical Energy and Capacitance

Electrical Energy and Capacitance: Part A

Current and Resistance Electric Current

Current and Resistance Electric Current: Part A

Direct-Current Circuits Sources of EMF

Direct-Current Circuits Sources of EMF: Part A

Magnetism Magnets

Magnetism Magnets: Part A

Induced Voltages and Inductance

Induced Voltages and Inductance: Part A

Alternating-Current Circuits and Electromagnetic Waves

Alternating-Current Circuits and Electromagnetic Waves: Part A

Reflection and Refraction of Light

Reflection and Refraction of Light: Part A

Mirrors and Lenses

Mirrors and Lenses: Part A

Wave Optics

Wave Optics: Part A

Optical Instruments

Optical Instruments: Part A

Relativity

Relativity: Part A

Quantum Physics Blackbody Radiation and Plancks Hypothesis

Quantum Physics Blackbody Radiation and Plancks Hypothesis: Part A

Atomic Physics

Atomic Physics: Part A

Nuclear Physics

Nuclear Physics: Part A

Nuclear Energy and Elementary Particles

Nuclear Energy and Elementary Particles: Part A

Particle Collisions, Mediating Photons, and Quark Structures: Exploring the Fundamentals of Physics

Filters

If two adjacent frequencies of an organ pipe closed at one end are 510 Hz and 635 Hz,what is the length of the organ pipe? (v_sound = 340 m/s)

A bat,flying at 6 m/s toward a wall,emits a chirp at 48 kHz.If the wall reflects this sound pulse,what is the frequency of the echo received by the bat? (v_sound = 340 m/s)

The density of a certain metal solid is 7 × 10³ kg/m³,and its Young's modulus is 13 × 10¹⁰ N/m².What is the speed of sound in this metal?

Comparing the speed of sound in liquids,gases,and solids,the speed of sound is usually lowest in and highest in .

Two cars,one in front of the other,are traveling down the highway at 44 m/s.The car behind sounds its horn,which has a frequency of 530 Hz.What is the frequency heard by the driver of the lead car? (v_sound = 340 m/s)