Question 1

Castor oil has a density of 956 kg/m3.If the speed of sound in castor oil is 1474 m/s, what is its adiabatic bulk modulus?

Accepted Answer

A) 1.77 × 109 N/m2 
B) 2.08 × 109 N/m2 
C) 5.71 × 109 N/m2 
D) 8.90 × 109 N/m2 
E) 9.22 × 109 N/m2

Question 2

The displacement of a vibrating string versus position along the string is shown in the figure.The periodic waves have a speed of 10.0 cm/s.A and B are two points on the string. 
-The tension in a taut rope is increased by a factor of 9.How does the speed of wave pulses on the rope change, if at all?

Accepted Answer

A) The speed remains the same. 
B) The speed is reduced by a factor of 3. 
C) The speed is reduced by a factor of 9. 
D) The speed is increased by a factor of 3. 
E) The speed is increased by a factor of 9.

Question 3

A wave has an amplitude of 0.35 m, a frequency of 1.05 × 106 Hz, and travels in the positive x direction at the speed of light, 3.00 × 108 m/s.Which one of the following equations correctly represents this wave?

Accepted Answer

A) y = 0.35 sin (6.60 × 106t - 0.022x) 
B) y = 0.35 sin (6.60 × 106t + 0.022x) 
C) y = 0.35 sin (286t - 1.05 × 106x) 
D) y = 0.35 sin (286t + 1.05 × 106x) 
E) y = 0.35 sin (1.05 × 106t + 3.00 × 108x)

Question 4

A car moving at 35 m/s approaches a stationary whistle that emits a 220 Hz sound.The speed of sound is 343 m/s.What is the speed of the sound relative to the driver of the car?

Accepted Answer

A) 300 m/s 
B) 308 m/s 
C) 340 m/s 
D) 365 m/s 
E) 378 m/s

Question 5

16-4
A periodic transverse wave is established on a string such that there are exactly two cycles traveling along a 3.0-m section of the string.The crests move at 20.0 m/s.
-What is the frequency of the wave?

Accepted Answer

A) 0.67 Hz 
B) 1.33 Hz 
C) 13 Hz 
D) 30 Hz 
E) 57 Hz

Question 6

How could the speed of the wave be increased?

Accepted Answer

A) by increasing the period 
B) by decreasing the amplitude 
C) by decreasing the frequency 
D) by increasing the tension in the string 
E) by increasing amplitude

Question 7

16-3
The car in the drawing is moving to the left at 35 m/s.The car's horn continuously emits a 2.20 × 10S1U1P12S1S1P0 Hz sound.The figure also shows the first two regions of compression of the emitted sound waves.The speed of sound is 343 m/s. 
-How far has the initial compression traveled when the second compression is emitted?

Accepted Answer

A) 0.77 m 
B) 1.56 m 
C) 7.7 m 
D) 15.5 m 
E) 35 m

Question 8

A transverse periodic wave described by the expression  (where y and x are in meters and t is in seconds) is established on a string.Which one of the following statements concerning this wave is false?

Accepted Answer

A) The wave is traveling in the negative x direction. 
B) The amplitude is 1.0 m. 
C) The frequency of the wave is 0.10 Hz. 
D) The wavelength of this wave is 2.0 m. 
E) The wave travels with speed 5.0 m/s.

Question 9

Two canoes are 10 m apart on a lake.Each bobs up and down with a period of 8.0 seconds.When one canoe is at its highest point, the other canoe is at its lowest point.Both canoes are always within a single cycle of the waves.Determine the speed of the waves.

Accepted Answer

A) 2.5 m/s 
B) 1.3 m/s 
C) 5.0 m/s 
D) 0.65 m/s 
E) 0.75 m/s

Question 10

Two fans are watching a baseball game from different positions.One fan is located directly behind home plate, 18.3 m from the batter.The other fan is located in the centerfield bleachers, 127 m from the batter.Both fans observe the batter strike the ball at the same time (because the speed of light is about a million times faster than that of sound), but the fan behind home plate hears the sound first.What is the time difference between hearing the sound at the two locations? Use 345 m/s as the speed of sound.

Accepted Answer

A) 0.316 s 
B) 0.368 s 
C) 3.17 s 
D) 1.89 s 
E) 0.053 s

Question 11

How long does it take a particle at the top of a crest to reach the bottom of an adjacent trough?

Accepted Answer

A) 0.018 s 
B) 0.038 s 
C) 0.075 s 
D) 0.150 s 
E) 0.30 s

Question 12

16-4
A periodic transverse wave is established on a string such that there are exactly two cycles traveling along a 3.0-m section of the string.The crests move at 20.0 m/s.
-What is the shortest horizontal distance from a crest to a point of zero acceleration?

Accepted Answer

A) 0.38 m 
B) 0.75 m 
C) 1.5 m 
D) 3.0 m 
E) 6.0 m

Question 13

16-5
A periodic traveling wave is generated on a string of linear density 8.0 × 10S1U1P1-S1S1P0S1U1P14S1S1P0 kg/m.Figure A shows the displacements of the particles in the string as a function of the position x along the string at t = 0 s.Figure B shows the displacement of the particle at x = 0 m as a function of time.The particle positions are measured from the left end of the string (x = 0 m) and the wave pulses move to the right. 
-What is the amplitude of the wave?

Accepted Answer

A) 0.01 m 
B) 0.02 m 
C) 0.04 m 
D) 0.07 m 
E) 0.7 m

Question 14

The displacement of a vibrating string versus position along the string is shown in the figure.The periodic waves have a speed of 10.0 cm/s.A and B are two points on the string. 
-A wave moves at a constant speed along a string.Which one of the following statements is false concerning the motion of particles in the string?

Accepted Answer

A) The particle speed is constant. 
B) The particle speed is not the same as the wave speed. 
C) The particle speed depends on the amplitude of the periodic motion of the source. 
D) The particle speed depends on the frequency of the periodic motion of the source. 
E) The particle speed is independent of the tension and linear density of the string.

Question 15

A physics student is asked to determine the length of a long, slender, copper bar by measuring the time required for a sound pulse to travel the length of the bar.The Young's modulus of copper is 1.1 × 1011 N/m2; and its density is 8890 kg/m3.The student finds that the time for the pulse to travel from one end to the other is 5.6 × 10-4 s.How long is the rod?

Accepted Answer

A) 11 m 
B) 7.8 m 
C) 5.5 m 
D) 2.0 m 
E) 0.45 m

Question 16

The intensity of a spherical wave 2.5 m from the source is 120 W/m2.What is the intensity at a point 9.0 m away from the source?

Accepted Answer

A) 9.3 W/m2 
B) 24 W/m2 
C) 53 W/m2 
D) 80 W/m2 
E) 270 W/m2

Question 17

16-5
A periodic traveling wave is generated on a string of linear density 8.0 × 10S1U1P1-S1S1P0S1U1P14S1S1P0 kg/m.Figure A shows the displacements of the particles in the string as a function of the position x along the string at t = 0 s.Figure B shows the displacement of the particle at x = 0 m as a function of time.The particle positions are measured from the left end of the string (x = 0 m) and the wave pulses move to the right. 
-What is the minimum time required for the particles to return to their respective positions at t = 0 s?

Accepted Answer

A) 0.1 s 
B) 0.2 s 
C) 0.3 s 
D) 0.4 s 
E) 0.7 s

Question 18

A train moving at a constant speed is passing a stationary observer on a platform.On one of the train cars, a flute player is continually playing the note known as concert A (f = 440 Hz).After the flute has passed, the observer hears the sound with a frequency of 415 Hz.What is the speed of the train? The speed of sound in air is 343 m/s.

Accepted Answer

A) 7.3 m/s 
B) 12 m/s 
C) 21 m/s 
D) 37 m/s 
E) 42 m/s

Question 19

A loudspeaker at the base of a cliff emits a pure tone of frequency 3000.0 Hz.A man jumps from rest from the top of the cliff and safely falls into a net below.How far has the man fallen at the instant he hears the frequency of the tone as 3218.0 Hz? The speed of sound is 343 m/s.

Accepted Answer

A) 12.2 m 
B) 15.3 m 
C) 31.7 m 
D) 46.8 m 
E) 61.0 m

Question 20

The speed of sound in fresh water at 293 K is 1482 m/s.At what temperature is the speed of sound in helium gas the same as that of fresh water at 293 K? Helium is considered a monatomic ideal gas ($\gamma$ = 1.67 and atomic mass = 4.003 u).

Accepted Answer

A) 313 K 
B) 377 K 
C) 442 K 
D) 525 K 
E) 633 K

Exam 16: Waves and Sound

Castor oil has a density of 956 kg/m³.If the speed of sound in castor oil is 1474 m/s, what is its adiabatic bulk modulus?

The displacement of a vibrating string versus position along the string is shown in the figure.The periodic waves have a speed of 10.0 cm/s.A and B are two points on the string. -The tension in a taut rope is increased by a factor of 9.How does the speed of wave pulses on the rope change, if at all?

A wave has an amplitude of 0.35 m, a frequency of 1.05 × 10⁶ Hz, and travels in the positive x direction at the speed of light, 3.00 × 10⁸ m/s.Which one of the following equations correctly represents this wave?

A car moving at 35 m/s approaches a stationary whistle that emits a 220 Hz sound.The speed of sound is 343 m/s.What is the speed of the sound relative to the driver of the car?

16-4 A periodic transverse wave is established on a string such that there are exactly two cycles traveling along a 3.0-m section of the string.The crests move at 20.0 m/s. -What is the frequency of the wave?

How could the speed of the wave be increased?

A transverse periodic wave described by the expression (where y and x are in meters and t is in seconds) is established on a string.Which one of the following statements concerning this wave is false?

Two canoes are 10 m apart on a lake.Each bobs up and down with a period of 8.0 seconds.When one canoe is at its highest point, the other canoe is at its lowest point.Both canoes are always within a single cycle of the waves.Determine the speed of the waves.

How long does it take a particle at the top of a crest to reach the bottom of an adjacent trough?

16-4 A periodic transverse wave is established on a string such that there are exactly two cycles traveling along a 3.0-m section of the string.The crests move at 20.0 m/s. -What is the shortest horizontal distance from a crest to a point of zero acceleration?

The intensity of a spherical wave 2.5 m from the source is 120 W/m².What is the intensity at a point 9.0 m away from the source?

A loudspeaker at the base of a cliff emits a pure tone of frequency 3000.0 Hz.A man jumps from rest from the top of the cliff and safely falls into a net below.How far has the man fallen at the instant he hears the frequency of the tone as 3218.0 Hz? The speed of sound is 343 m/s.

The speed of sound in fresh water at 293 K is 1482 m/s.At what temperature is the speed of sound in helium gas the same as that of fresh water at 293 K? Helium is considered a monatomic ideal gas ( $\gamma$ = 1.67 and atomic mass = 4.003 u) .

Exam 16: Waves and Sound

Castor oil has a density of 956 kg/m3.If the speed of sound in castor oil is 1474 m/s, what is its adiabatic bulk modulus?

A wave has an amplitude of 0.35 m, a frequency of 1.05 × 106 Hz, and travels in the positive x direction at the speed of light, 3.00 × 108 m/s.Which one of the following equations correctly represents this wave?

A car moving at 35 m/s approaches a stationary whistle that emits a 220 Hz sound.The speed of sound is 343 m/s.What is the speed of the sound relative to the driver of the car?

16-4 A periodic transverse wave is established on a string such that there are exactly two cycles traveling along a 3.0-m section of the string.The crests move at 20.0 m/s. -What is the frequency of the wave?

How could the speed of the wave be increased?

A transverse periodic wave described by the expression (where y and x are in meters and t is in seconds) is established on a string.Which one of the following statements concerning this wave is false?

Two canoes are 10 m apart on a lake.Each bobs up and down with a period of 8.0 seconds.When one canoe is at its highest point, the other canoe is at its lowest point.Both canoes are always within a single cycle of the waves.Determine the speed of the waves.

How long does it take a particle at the top of a crest to reach the bottom of an adjacent trough?

16-4 A periodic transverse wave is established on a string such that there are exactly two cycles traveling along a 3.0-m section of the string.The crests move at 20.0 m/s. -What is the shortest horizontal distance from a crest to a point of zero acceleration?

The intensity of a spherical wave 2.5 m from the source is 120 W/m2.What is the intensity at a point 9.0 m away from the source?

A loudspeaker at the base of a cliff emits a pure tone of frequency 3000.0 Hz.A man jumps from rest from the top of the cliff and safely falls into a net below.How far has the man fallen at the instant he hears the frequency of the tone as 3218.0 Hz? The speed of sound is 343 m/s.

The speed of sound in fresh water at 293 K is 1482 m/s.At what temperature is the speed of sound in helium gas the same as that of fresh water at 293 K? Helium is considered a monatomic ideal gas ( γ\gammaγ = 1.67 and atomic mass = 4.003 u) .

Castor oil has a density of 956 kg/m³.If the speed of sound in castor oil is 1474 m/s, what is its adiabatic bulk modulus?

A wave has an amplitude of 0.35 m, a frequency of 1.05 × 10⁶ Hz, and travels in the positive x direction at the speed of light, 3.00 × 10⁸ m/s.Which one of the following equations correctly represents this wave?

The intensity of a spherical wave 2.5 m from the source is 120 W/m².What is the intensity at a point 9.0 m away from the source?

The speed of sound in fresh water at 293 K is 1482 m/s.At what temperature is the speed of sound in helium gas the same as that of fresh water at 293 K? Helium is considered a monatomic ideal gas ( $\gamma$ = 1.67 and atomic mass = 4.003 u) .