Question 1

A series of ocean waves,2.5 m between crests,move past at 2.0 waves/s.Find their speed.

Accepted Answer

A)  2.5 m/s 
B)  5.0 m/s 
C)  8.0 m/s 
D)  10 m/s 
A)  2.5 m/s 
B)  5.0 m/s 
C)  8.0 m/s 
D)  10 m/s

Question 2

A tuning fork is sounded above an adjustable length resonating tube (one end closed),which resonates at a length of 0.250 m and again at 0.750 m.If the tube length were extended further,at what point will the tuning fork again create a resonance condition?

Accepted Answer

A)  1.75 m 
B)  1.50 m 
C)  1.25 m 
D)  1.00 m 
A)  1.75 m 
B)  1.50 m 
C)  1.25 m 
D)  1.00 m

Question 3

What is the next harmonic frequency over the fundamental for an organ pipe 1.50 m in length,closed at one end? The speed of sound in air is 340 m/s.

Accepted Answer

A)  227 Hz 
B)  170 Hz 
C)  113 Hz 
D)  56.7 Hz 
A)  227 Hz 
B)  170 Hz 
C)  113 Hz 
D)  56.7 Hz

Question 4

A 2.00-m long organ pipe is open at one end and closed at the other.Its fundamental tone has wavelength:

Accepted Answer

A)  8.00 m. 
B)  4.00 m. 
C)  2.00 m. 
D)  1.00 m. 
A)  8.00 m. 
B)  4.00 m. 
C)  2.00 m. 
D)  1.00 m.

Question 5

You stand by the railroad tracks as a train passes by.You hear a 950-Hz frequency when the train approaches,which changes to 820 Hz as it goes away.How fast is the train moving? The speed of sound in air is 340 m/s.

Accepted Answer

A)  14.0 m/s 
B)  20.0 m/s 
C)  25.0 m/s 
D)  37.8 m/s 
A)  14.0 m/s 
B)  20.0 m/s 
C)  25.0 m/s 
D)  37.8 m/s

Question 6

If two adjacent frequencies of an organ pipe closed at one end are 500 Hz and 700 Hz,what is the length of the organ pipe? (vsound = 340 m/s)

Accepted Answer

A)  0.85 m 
B)  1.25 m 
C)  1.50 m 
D)  1.70 m 
A)  0.85 m 
B)  1.25 m 
C)  1.50 m 
D)  1.70 m

Question 7

A tuning fork is sounded above an adjustable length resonating tube (one end closed),which resonates at a length of 0.250 m and again at 0.750 m.What is the frequency of the fork when the speed of sound is taken to be 340 m/s?

Accepted Answer

A)  340 Hz 
B)  680 Hz 
C)  1020 Hz 
D)  170 Hz 
A)  340 Hz 
B)  680 Hz 
C)  1020 Hz 
D)  170 Hz

Question 8

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 9

While standing at a crosswalk,you hear a frequency of 540 Hz from an approaching police car.After the police car passes,its frequency is 480 Hz.What is the speed of the police car? (speed of sound = 340 m/s)

Accepted Answer

A)  13.1 m/s 
B)  17.4 m/s 
C)  20.0 m/s 
D)  26.2 m/s 
A)  13.1 m/s 
B)  17.4 m/s 
C)  20.0 m/s 
D)  26.2 m/s

Question 10

A very loud train whistle has an acoustic power output of 80 W.If the sound energy spreads out spherically,what is the intensity level in dB at a distance of 100 meters from the train? (I0 = 10−12 W/m2)

Accepted Answer

A)  78.3 dB 
B)  88.0 dB 
C)  92.8 dB 
D)  95.0 dB 
A)  78.3 dB 
B)  88.0 dB 
C)  92.8 dB 
D)  95.0 dB

Question 11

The speed of sound at 0°C is 331 m/s.What is the speed of sound at 32°C? (0°C = 273 K)

Accepted Answer

A)  346 m/s 
B)  356 m/s 
C)  343 m/s 
D)  350 m/s 
A)  346 m/s 
B)  356 m/s 
C)  343 m/s 
D)  350 m/s

Question 12

If one-half of the members of a symphony orchestra are absent because of head colds,thus reducing the overall intensity of sound by 50%,what will be the reduction in the decibel level?

Accepted Answer

A)  5 dB 
B)  3 dB 
C)  48 dB 
D)  1.7 dB 
A)  5 dB 
B)  3 dB 
C)  48 dB 
D)  1.7 dB

Question 13

A phase difference of 480° corresponds to what wavelength difference?

Accepted Answer

A)  3λ 
B)  3λ/2 
C)  3λ/4 
D)  4λ/3 
A)  3λ 
B)  3λ/2 
C)  3λ/4 
D)  4λ/3

Question 14

Two tuning forks sounding together result in a beat frequency of 3 Hz.If the frequency of one of the forks is 512 Hz,what is the frequency of the other?

Accepted Answer

A)  509 Hz or 515 Hz 
B)  105 Hz 
C)  518 Hz or 506 Hz 
D)  85 Hz 
A)  509 Hz or 515 Hz 
B)  105 Hz 
C)  518 Hz or 506 Hz 
D)  85 Hz

Question 15

By what amount does the sound intensity decrease when the distance to the source triples?

Accepted Answer

A)  9.0 dB 
B)  9.5 dB 
C)  6.0 dB 
D)  3.5 dB 
A)  9.0 dB 
B)  9.5 dB 
C)  6.0 dB 
D)  3.5 dB

Question 16

A flute behaves like a tube open at both ends.If its length is 70.0 cm,and the speed of sound is 340 m/s,what is its fundamental frequency in Hz?

Accepted Answer

A)  121 Hz 
B)  159 Hz 
C)  243 Hz 
D)  260 Hz 
A)  121 Hz 
B)  159 Hz 
C)  243 Hz 
D)  260 Hz

Question 17

Two cars,one in front of the other,are traveling down the highway at 25 m/s.The car behind sounds its horn,which has a frequency of 540 Hz.What is the frequency heard by the driver of the lead car? (vsound = 340 m/s)

Accepted Answer

A)  463 Hz 
B)  540 Hz 
C)  579 Hz 
D)  500 Hz 
A)  463 Hz 
B)  540 Hz 
C)  579 Hz 
D)  500 Hz

Question 18

Doubling the power output from a speaker emitting a single frequency will result in what increase in loudness?

Accepted Answer

A)  0.33 dB 
B)  3.0 dB 
C)  4.8 dB 
D)  9.0 dB 
A)  0.33 dB 
B)  3.0 dB 
C)  4.8 dB 
D)  9.0 dB

Question 19

What sound level change most nearly corresponds to a factor of three change in intensity?

Accepted Answer

A)  0.5 dB 
B)  2 dB 
C)  3 dB 
D)  5 dB 
A)  0.5 dB 
B)  2 dB 
C)  3 dB 
D)  5 dB

Question 20

A bat,flying at 3.00 m/s toward a wall,emits a chirp at 50.0 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)  51.5 kHz 
B)  51.2 kHz 
C)  40.8 kHz 
D)  50.9 kHz 
A)  51.5 kHz 
B)  51.2 kHz 
C)  40.8 kHz 
D)  50.9 kHz

Exam 13: Vibrations and Waves: Part A

A series of ocean waves,2.5 m between crests,move past at 2.0 waves/s.Find their speed.

A tuning fork is sounded above an adjustable length resonating tube (one end closed),which resonates at a length of 0.250 m and again at 0.750 m.If the tube length were extended further,at what point will the tuning fork again create a resonance condition?

What is the next harmonic frequency over the fundamental for an organ pipe 1.50 m in length,closed at one end? The speed of sound in air is 340 m/s.

A 2.00-m long organ pipe is open at one end and closed at the other.Its fundamental tone has wavelength:

You stand by the railroad tracks as a train passes by.You hear a 950-Hz frequency when the train approaches,which changes to 820 Hz as it goes away.How fast is the train moving? The speed of sound in air is 340 m/s.

If two adjacent frequencies of an organ pipe closed at one end are 500 Hz and 700 Hz,what is the length of the organ pipe? (vsound = 340 m/s)

A tuning fork is sounded above an adjustable length resonating tube (one end closed),which resonates at a length of 0.250 m and again at 0.750 m.What is the frequency of the fork when the speed of sound is taken to be 340 m/s?

Which of the following ranges corresponds to the shortest wavelengths?

While standing at a crosswalk,you hear a frequency of 540 Hz from an approaching police car.After the police car passes,its frequency is 480 Hz.What is the speed of the police car? (speed of sound = 340 m/s)

A very loud train whistle has an acoustic power output of 80 W.If the sound energy spreads out spherically,what is the intensity level in dB at a distance of 100 meters from the train? (I0 = 10−12 W/m2)

The speed of sound at 0°C is 331 m/s.What is the speed of sound at 32°C? (0°C = 273 K)

If one-half of the members of a symphony orchestra are absent because of head colds,thus reducing the overall intensity of sound by 50%,what will be the reduction in the decibel level?

A phase difference of 480° corresponds to what wavelength difference?

Two tuning forks sounding together result in a beat frequency of 3 Hz.If the frequency of one of the forks is 512 Hz,what is the frequency of the other?

By what amount does the sound intensity decrease when the distance to the source triples?

A flute behaves like a tube open at both ends.If its length is 70.0 cm,and the speed of sound is 340 m/s,what is its fundamental frequency in Hz?

Two cars,one in front of the other,are traveling down the highway at 25 m/s.The car behind sounds its horn,which has a frequency of 540 Hz.What is the frequency heard by the driver of the lead car? (vsound = 340 m/s)

Doubling the power output from a speaker emitting a single frequency will result in what increase in loudness?

What sound level change most nearly corresponds to a factor of three change in intensity?

A bat,flying at 3.00 m/s toward a wall,emits a chirp at 50.0 kHz.If the wall reflects this sound pulse,what is the frequency of the echo received by the bat? (vsound = 340 m/s)

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

Sound

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

If two adjacent frequencies of an organ pipe closed at one end are 500 Hz and 700 Hz,what is the length of the organ pipe? (v_sound = 340 m/s)

A very loud train whistle has an acoustic power output of 80 W.If the sound energy spreads out spherically,what is the intensity level in dB at a distance of 100 meters from the train? (I₀ = 10−¹² W/m²)

Two cars,one in front of the other,are traveling down the highway at 25 m/s.The car behind sounds its horn,which has a frequency of 540 Hz.What is the frequency heard by the driver of the lead car? (v_sound = 340 m/s)

A bat,flying at 3.00 m/s toward a wall,emits a chirp at 50.0 kHz.If the wall reflects this sound pulse,what is the frequency of the echo received by the bat? (v_sound = 340 m/s)