Question 1

A bell emits sound energy uniformly in all directions at a rate of 4.00 × 10-3 W.What is the intensity of the wave 100.0 m from the bell?

Accepted Answer

A) 3.18 × 10-8 W/m2 
B) 3.14 × 10-7 W/m2 
C) 5.02 × 10-2 W/m2 
D) 5.02 × 102 W/m2 
E) 6.28 × 107 W/m2 
A) 3.18 × 10-8 W/m2 
B) 3.14 × 10-7 W/m2 
C) 5.02 × 10-2 W/m2 
D) 5.02 × 102 W/m2 
E) 6.28 × 107 W/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.  
-A steel wire of mass 0.400 kg and length 0.640 m supports a 102-kg block.The wire is struck exactly at its midpoint causing a small displacement.How long does it take the peak of this displacement to reach the top of the wire?

Accepted Answer

A) 2.00 × 10-3 s 
B) 4.00 × 10-3 s 
C) 6.00 × 10-3 s 
D) 8.00 × 10-3 s 
E) 1.60 × 10-2 s 
A) 2.00 × 10-3 s 
B) 4.00 × 10-3 s 
C) 6.00 × 10-3 s 
D) 8.00 × 10-3 s 
E) 1.60 × 10-2 s

Question 3

The speaker and two microphones shown in the figure are arranged inside a sealed container filled with neon gas.The wires from the microphones are connected to an oscilloscope (not shown).The signal from the microphones is monitored beginning at time t = 0 s when a sound pulse is emitted from the speaker.The pulse is picked up by microphone 1 at t1 = 1.150 × 10-2 s and by microphone 2 at t2 = 1.610 × 10-2 s.What is the speed of sound in neon gas?

Accepted Answer

A) 124 m/s 
B) 174 m/s 
C) 362 m/s 
D) 435 m/s 
E) 724 m/s 
A) 124 m/s 
B) 174 m/s 
C) 362 m/s 
D) 435 m/s 
E) 724 m/s

Question 4

16-2
The diagram shows the various positions of a child in motion on a swing.Somewhere in front of the child a stationary whistle is blowing.  
-At which position(s) will the child hear the highest frequency for the sound from the whistle?

Accepted Answer

A) at both A and D 
B) at B when moving toward A 
C) at B when moving toward C 
D) at C when moving toward B 
E) at C when moving toward D 
A) at both A and D 
B) at B when moving toward A 
C) at B when moving toward C 
D) at C when moving toward B 
E) at C when moving toward D

Question 5

At a distance of 5.0 m from a point sound source, the sound intensity level is 110 dB.At what distance is the intensity level 95 dB?

Accepted Answer

A) 5.0 m 
B) 7.1 m 
C) 14 m 
D) 28 m 
E) 42 m 
A) 5.0 m 
B) 7.1 m 
C) 14 m 
D) 28 m 
E) 42 m

Question 6

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.  
-What is the frequency of the wave?

Accepted Answer

A) 0.60 Hz 
B) 0.90 Hz 
C) 1.1 Hz 
D) 1.3 Hz 
E) 1.7 Hz 
A) 0.60 Hz 
B) 0.90 Hz 
C) 1.1 Hz 
D) 1.3 Hz 
E) 1.7 Hz

Question 7

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 certain string on a piano is tuned to produce middle C (f = 261.63 Hz) by carefully adjusting the tension in the string.For a fixed wavelength, what is the frequency when this tension is tripled?

Accepted Answer

A) 87.21 Hz 
B) 151.05 Hz 
C) 370.00 Hz 
D) 453.16 Hz 
E) 784.89 Hz 
A) 87.21 Hz 
B) 151.05 Hz 
C) 370.00 Hz 
D) 453.16 Hz 
E) 784.89 Hz

Question 8

16-2
The diagram shows the various positions of a child in motion on a swing.Somewhere in front of the child a stationary whistle is blowing.  
-At which position(s) will the child hear the same frequency as that heard by a stationary observer standing next to the whistle?

Accepted Answer

A) at both A and D 
B) at B when moving toward A 
C) at B when moving toward C 
D) at C when moving toward B 
E) at C when moving toward D 
A) at both A and D 
B) at B when moving toward A 
C) at B when moving toward C 
D) at C when moving toward B 
E) at C when moving toward D

Question 9

What is the wavelength of a wave with a speed of 9.0 m/s and a period of 0.33 s?

Accepted Answer

A) 0.33 m 
B) 1.5 m 
C) 3.0 m 
D) 13 m 
E) 27 m 
A) 0.33 m 
B) 1.5 m 
C) 3.0 m 
D) 13 m 
E) 27 m

Question 10

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.  
-What is the wavelength of the wave?

Accepted Answer

A) 3.0 cm 
B) 6.0 cm 
C) 9.0 cm 
D) 12 cm 
E) 15 cm 
A) 3.0 cm 
B) 6.0 cm 
C) 9.0 cm 
D) 12 cm 
E) 15 cm

Question 11

A periodic wave travels along a stretched string in the direction shown by the arrow.The sketch shows a "snapshot" of the pulse at a certain instant.Points A, B, and C are on the string.Which entry in the table below correctly describes how particles of string between A and B and between B and C are moving?   between A and B between B and C

Accepted Answer

A) down down 
B) up down 
C) left right 
D) up up 
E) down up 
A) down down 
B) up down 
C) left right 
D) up up 
E) down up

Question 12

A wave is traveling at 35 m/s on a string with a linear density of 0.082 kg/m.What is the tension in the string?

Accepted Answer

A) 0.28 N 
B) 0.56 N 
C) 2.5 N 
D) 5.0 N 
E) 10 N 
A) 0.28 N 
B) 0.56 N 
C) 2.5 N 
D) 5.0 N 
E) 10 N

Question 13

How far must one stand from a 5-mW point sound source if the intensity at that location is at the hearing threshold? Assume the sound waves travel to the listener without being disturbed.

Accepted Answer

A) 500 m 
B) 1 km 
C) 2 km 
D) 4 km 
E) 20 km 
A) 500 m 
B) 1 km 
C) 2 km 
D) 4 km 
E) 20 km

Question 14

A bell is ringing inside of a sealed glass jar that is connected to a vacuum pump.Initially, the jar is filled with air.What does one hear as the air is slowly removed from the jar by the pump?

Accepted Answer

A) The sound intensity from the bell gradually decreases. 
B) The frequency of the sound from the bell gradually increases. 
C) The frequency of the sound from the bell gradually decreases. 
D) The speed of the sound from the bell gradually increases. 
E) The intensity of the sound from the bell does not change. 
A) The sound intensity from the bell gradually decreases. 
B) The frequency of the sound from the bell gradually increases. 
C) The frequency of the sound from the bell gradually decreases. 
D) The speed of the sound from the bell gradually increases. 
E) The intensity of the sound from the bell does not change.

Question 15

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 wavelength of the wave?

Accepted Answer

A) 0.005 m 
B) 0.010 m 
C) 0.015 m 
D) 0.020 m 
E) 0.025 m 
A) 0.005 m 
B) 0.010 m 
C) 0.015 m 
D) 0.020 m 
E) 0.025 m

Question 16

A source moving through water at 10.0 m/s generates water waves with a frequency of 5.0 Hz.The speed of these water waves relative to the water surface is 20.0 m/s.The source approaches an observer who is at rest in the water.What wavelength would be measured for these waves by the stationary observer?

Accepted Answer

A) 1.0 m 
B) 2.0 m 
C) 4.0 m 
D) 6.0 m 
E) 8.0 m 
A) 1.0 m 
B) 2.0 m 
C) 4.0 m 
D) 6.0 m 
E) 8.0 m

Question 17

An unstretched spring has a length of 0.30 m.When the spring is stretched to a total length of 0.60 m, it supports traveling waves moving at 4.5 m/s.How fast will waves travel on this spring if it is stretched to 0.90 m?

Accepted Answer

A) 2.3 m/s 
B) 4.5 m/s 
C) 6.4 m/s 
D) 9.0 m/s 
E) 10.8 m/s 
A) 2.3 m/s 
B) 4.5 m/s 
C) 6.4 m/s 
D) 9.0 m/s 
E) 10.8 m/s

Question 18

Of the three traveling waves listed below, which one(s) is(are) traveling in the +x direction?

Accepted Answer

A) 1 only 
B) 2 only 
C) 3 only 
D) 1, 2, and 3 
E) 2 and 3 only 
A) 1 only 
B) 2 only 
C) 3 only 
D) 1, 2, and 3 
E) 2 and 3 only

Question 19

A guitar string is plucked and set into vibration.The vibrating string disturbs the surrounding air, resulting in a sound wave.Which entry in the table below is correct? wave in the string sound wave in air

Accepted Answer

A) The wave is transverse.yes yes 
B) The wave speed increases no yes if the temperature rises. 
C) The wave is longitudinal.yes yes 
D) The wave is transmitted no yes by particle vibrations. 
E) The wave transports energy.yes no 
A) The wave is transverse.yes yes 
B) The wave speed increases no yes if the temperature rises. 
C) The wave is longitudinal.yes yes 
D) The wave is transmitted no yes by particle vibrations. 
E) The wave transports energy.yes no

Question 20

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 frequency of sound heard by the driver of the car?

Accepted Answer

A) 198 Hz 
B) 220 Hz 
C) 245 Hz 
D) 282 Hz 
E) 340 Hz 
A) 198 Hz 
B) 220 Hz 
C) 245 Hz 
D) 282 Hz 
E) 340 Hz

Exam 16: Waves and Sound

A bell emits sound energy uniformly in all directions at a rate of 4.00 × 10-3 W.What is the intensity of the wave 100.0 m from the bell?

16-2 The diagram shows the various positions of a child in motion on a swing.Somewhere in front of the child a stationary whistle is blowing. -At which position(s) will the child hear the highest frequency for the sound from the whistle?

At a distance of 5.0 m from a point sound source, the sound intensity level is 110 dB.At what distance is the intensity level 95 dB?

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. -What is the frequency of the wave?

16-2 The diagram shows the various positions of a child in motion on a swing.Somewhere in front of the child a stationary whistle is blowing. -At which position(s) will the child hear the same frequency as that heard by a stationary observer standing next to the whistle?

What is the wavelength of a wave with a speed of 9.0 m/s and a period of 0.33 s?

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. -What is the wavelength of the wave?

A wave is traveling at 35 m/s on a string with a linear density of 0.082 kg/m.What is the tension in the string?

How far must one stand from a 5-mW point sound source if the intensity at that location is at the hearing threshold? Assume the sound waves travel to the listener without being disturbed.

A bell is ringing inside of a sealed glass jar that is connected to a vacuum pump.Initially, the jar is filled with air.What does one hear as the air is slowly removed from the jar by the pump?

An unstretched spring has a length of 0.30 m.When the spring is stretched to a total length of 0.60 m, it supports traveling waves moving at 4.5 m/s.How fast will waves travel on this spring if it is stretched to 0.90 m?

Of the three traveling waves listed below, which one(s) is(are) traveling in the +x direction?

A guitar string is plucked and set into vibration.The vibrating string disturbs the surrounding air, resulting in a sound wave.Which entry in the table below is correct? wave in the string sound wave in air

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 frequency of sound heard by the driver of the car?

Introduction and Mathematical Concepts

Kinematics in One Dimension

Kinematics in Two Dimensions

Forces and Newtons Laws of Motion

Dynamics of Uniform Circular Motion

Work and Energy

Impulse and Momentum

Rotational Kinematics

Rotational Dynamics

Simple Harmonic Motion and Elasticity

Fluids

Temperature and Heat

The Transfer of Heat

The Ideal Gas Law and Kinetic Theory

Thermodynamics

The Principle of Linear Superposition and Interference Phenomena

Electric Forces and Electric Fields

Electric Potential Energy and the Electric Potential

Electric Circuits

Magnetic Forces and Magnetic Fields

Electromagnetic Induction

Alternating Current Circuits

Electromagnetic Waves

The Reflection of Light: Mirrors

The Refraction of Light: Lenses and Optical Instruments

Interference and the Wave Nature of Light

Special Relativity

Particles and Waves

The Nature of the Atom

Nuclear Physics and Radioactivity

Ionizing Radiation, Nuclear Energy, and Elementary Particles

Filters

A bell emits sound energy uniformly in all directions at a rate of 4.00 × 10^-³ W.What is the intensity of the wave 100.0 m from the bell?