Deck 12: Waves and Sound

Question 1

The explanation for refraction must involve a change in

A) wavelength.
B) speed.
C) frequency.
D) All of the above choices are true.
E) None of the above choices are true.

Answer 1

speed.

Question 2

The frequencies of sound that carry farther in air are

A) high.
B) ultrasonic.
C) low.

Answer 2

low.

Question 3

If the waves are going by at the same frequency, the wave that has the greatest speed will have the greatest

A) frequency.
B) amplitude.
C) length.
D) None of the above choices are true.

Answer 3

length.

Question 4

A Doppler effect occurs when a source of sound moves

A) toward you.
B) at right angles to you.
C) both of these
D) none of these

Question 5

A wave travels an average distance of 6 meters in one second. What is the wave's velocity?

A) less than 0.2 m/s
B) 6 m/s
C) 1 m/s
D) 3 m/s
E) more than 6 m/s

Question 6

The source of a sonic boom

A) is not itself an emitter of sound.
B) must itself be an emitter of sound.
C) may or may not be an emitter of sound.

Question 7

An object that completes 20 vibrations in 10 seconds has a frequency of

A) 2 hertz.
B) 0.5 hertz.
C) 1 hertz.
D) 200 hertz.

Question 8

The loudness of a musical sound is a measure of the sound wave's

A) wavelength.
B) speed.
C) frequency.
D) amplitude.
E) all of these

Question 9

A sound source of high frequency emits a high

A) speed.
B) pitch.
C) amplitude.
D) all of these
E) none of these

Question 10

In a longitudinal wave the compressions and rarefactions travel in

A) opposite directions.
B) the same direction.
C) a vacuum.

Question 11

Sound travels faster in

A) air.
B) a vacuum.
C) water.
D) steel.
E) Sound travels at about the same speed in all of the above media.

Question 12

A skipper on a boat notices wave crests passing the anchor chain every 5 seconds. The skipper estimates the distance between crests is 15 m. What is the speed of the water waves?

A) 5 m/s
B) 3 m/s
C) 15 m/s
D) not enough information given

Question 13

An observer on the ground hears a sonic boom which is created by an airplane flying at a speed

A) equal to the speed of sound.
B) just below the speed of sound.
C) greater than the speed of sound.
D) All of the above choices are true.
E) None of the above choices are true.

Question 14

A floating object oscillates up and down 2 complete cycles in 1 second as a water wave of wavelength 5 meters passes by. The speed of the wave is

A) 10 m/s.
B) 2 m/s.
C) 5 m/s.
D) 15 m/s.
E) none of these

Question 15

The vibrations of a longitudinal wave move in a direction

A) that changes with speed.
B) at right angles to the direction of wave travel.
C) along the direction of wave travel.

Question 16

High pitched sound has a high

A) number of partial tones.
B) speed.
C) frequency.
D) All of the above choices are correct.
E) None of the above choices are correct.

Question 17

The amplitude of a particular wave is 1 meter. The top-to-bottom distance of the disturbance is

A) 1 m.
B) 0.5 m.
C) 2 m.
D) none of these

Question 18

The frequency of a simple pendulum depends on

A) its mass.
B) the acceleration due to gravity.
C) its length.
D) all of these
E) two of these

Question 19

A wave oscillates up and down two complete cycles each second. If the wave travels an average distance of 6 meters in one second, its wavelength is

A) 2 m.
B) 0.5 m.
C) 6 m.
D) 3 m.
E) 1 m.

Question 20

You dip your finger repeatedly into water and make waves. If you dip your finger more frequently, the wavelength of the waves

A) lengthens.
B) shortens.
C) stays the same.

Question 21

Reverberation is actually a case of

A) forced vibrations.
B) sound interference.
C) resonance.
D) re-echoed sound.
E) None of the above choices are correct..

Question 22

For light, a red shift indicates that the light source is moving

A) away from you.
B) at right angles to you.
C) toward you.
D) actually, all of these
E) none of these

Question 23

The period of the second hand on a clock is

A) 1/60 second.
B) 1 second.
C) 12 hours.
D) 3600 seconds.
E) 60 seconds.

Question 24

Compressions and rarefactions are characteristic of

A) longitudinal waves.
B) transverse waves.
C) both longitudinal and transverse waves.
D) Neither of the above choices are correct.

Question 25

Which of the following is not a transverse wave?

A) light
B) sound
C) radio
D) all of these
E) none of these

Question 26

When the handle of a tuning fork is held solidly against a table, the sound becomes louder and the time that the fork keeps vibrating

A) becomes shorter.
B) becomes longer.
C) remains the same.

Question 27

Compressions and rarefactions normally travel in

A) opposite directions in a wave.
B) the same direction in a wave.
C) directions that are at right angles to the wave direction.

Question 28

Suppose a simple pendulum is suspended in an elevator. When the elevator is accelerating upward, the frequency of the pendulum

A) decreases.
B) increases.
C) doesn't change.

Question 29

Inhaling helium increases the pitch of your voice. The reason for this is that sound travels

A) slower in helium than in air.
B) faster in helium than in air.
C) the same speed in helium, but the wavelength is greater.

Question 30

A bow wave is produced when a wave source moves

A) faster than the waves it produces.
B) as fast as the waves it produces.
C) nearly as fast as the waves it produces.

Question 31

The natural frequency of an object depends on its

A) size, shape and elasticity.
B) shape and elasticity.
C) size and shape.
D) size and elasticity.

Question 32

Wave interference occurs for

A) water waves.
B) sound waves.
C) light waves.
D) All of the above choices are correct.
E) None of the above choices are correct.

Question 33

A 1056-hertz tuning fork is sounded at the same time a piano note is struck. You hear three beats per second. What is the frequency of the piano string?

A) not enough information to be certain
B) 3168 hertz
C) 1059 hertz
D) 1056 hertz
E) 1053 hertz

Question 34

Sound will be louder if a struck tuning fork is held

A) with its base against a table top.
B) in the air.
C) with its prongs in shallow water.
D) in your closed fist.

Question 35

A piano tuner knows that a key on the piano is tuned to the frequency of his tuning fork when he strikes them at the same time and the number of beats he hears each second is

A) 0.
B) 1.
C) 2.
D) 3.
E) 4.

Question 36

A fishing-boat captain returns to port saying, "It's rough out there - the waves are 4 meters high." He probably means that the amplitude of the waves is

A) 4 m.
B) 3 m.
C) 2 m.
D) 1 m.

Question 37

A 340-hertz sound wave travels at 340 m/s in air with a wavelength of

A) 100 m.
B) 10 m.
C) 1 m.
D) 1000 m.
E) None of the above choices are correct.

Question 38

A jet traveling at 1500 km/hr passes between observers A and B. In a short time a sonic boom will be heard by

A) observer A , observer B, and the pilot of the jet.
B) observer A only.
C) observer B only.
D) observers A and B, but not the pilot.

Question 39

Radio waves travel at the speed of light, 300,000 km/s. The wavelength of a radio wave received at 100 megahertz is

A) 300 m.
B) 3.0 m.
C) 30 m.
D) 0.3 m.
E) none of these

Question 40

The energy of sound in air eventually becomes

A) weaker and weaker until it disappears.
B) increased internal energy of the air.
C) cancelled by destructive interference.
D) cancelled by both destructive and constructive interference.

Question 41

The source of every sound is something that is

A) undergoing simple harmonic motion.
B) vibrating.
C) accelerating.
D) moving.
E) a net emitter of energy.

Question 42

When the speed of sound near the ground is greater than it is at higher altitudes, the sound tends to be bent

A) upward.
B) downward.
C) to the right.
D) to the left.
E) None of the above choices are correct.

Question 43

Two wave crests are generated at opposite ends of a long rope. Will there be an instant in which the rope's amplitude is zero everywhere?

A) Yes, if the waves have the same amplitude
B) Yes, if the waves have different amplitudes.
C) No.

Question 44

During a single period, the distance traveled by a wave is

A) one wavelength.
B) two wavelengths.
C) one-half wavelength.

Question 45

A general rule for estimating the distance in kilometers between an observer and a lightning bolt is to count the number of seconds between seeing the lightning and hearing it, and dividing by

A) 2.
B) 3.
C) 4.
D) 5.
E) none of these

Question 46

The phenomenon of beats results from sound

A) reflection.
B) interference.
C) refraction.
D) all of these
E) none of these

Question 47

An object that completes 10 vibrations in 20 seconds has a frequency of

A) 200 hertz.
B) 0.5 hertz.
C) 2 hertz.

Question 48

If waves are going by at the same speed, the wave with the greatest period of oscillation is the wave that has the greatest

A) amplitude.
B) frequency.
C) length.
D) None of the above choices are true.

Question 49

As a train of water waves goes by, a piece of cork floating on the water bobs up and down one complete cycle each second. The waves are 2 meters long. What is the speed of the wave?

A) 2 m/s
B) 4 m/s
C) 0.50 m/s
D) 0.25 m/s
E) 1.0 m/s

Question 50

Sound waves cannot travel in

A) water.
B) a vacuum.
C) steel.
D) air.
E) any of the above media

Question 51

If at a concert you run toward the orchestra, the frequency of the sound you hear will be

A) increased.
B) decreased.
C) neither decreased nor increased.

Question 52

If at a concert, a wind blows directly from the orchestra toward you, the speed of the sound you hear will be

A) decreased.
B) increased.
C) neither decreased nor increased.

Question 53

At a concert the oboe is playing a long steady note as you walk away from the stage at an accelerating velocity toward the rest room. The pitch of the sound that you hear, is

A) continually increasing.
B) continually decreasing.
C) steady but lower than normal.
D) steady but higher than normal
E) None of the above choices are correct.

Question 54

How many vibrations per second are associated with a 101-MHz radio wave?

A) less than 101,000,000
B) more than 101,000,000
C) 101,000,000

Question 55

If you double the frequency of a vibrating object, its period

A) is quartered.
B) doubles.
C) halves.

Question 56

The pendulum with the greatest frequency is the pendulum with the

A) shortest amplitude.
B) greatest amplitude.
C) shortest period and the shortest length.
D) shortest period.
E) shortest length.

Question 57

As a source of continuous sound approaches a constant speed, you will be aware of an apparent increasing of its

A) loudness, frequency, and wavelength.
B) loudness and frequency.
C) loudness and wavelength.
D) frequency and wavelength.
E) None of the above choices are correct.

Question 58

A floating leaf oscillates up and down two complete cycles in one second as a water wave passes by. The wave's wavelength is 10 meters. What is the wave's speed?

A) 10 m/s
B) 20 m/s
C) 40 m/s
D) 2 m/s
E) more than 40 m/s

Question 59

Sound travels faster in air if the air temperature is

A) warm.
B) average.
C) cold.

Question 60

As we grow older, we have the greatest difficulty hearing frequencies that are

A) high.
B) mid-range.
C) low.

Question 61

As a supersonic craft increases in speed, the angle of its V-shaped shock wave becomes

A) narrower.
B) wider.
C) neither

Question 62

The pitch of a musical sound depends on the sound wave's

A) frequency.
B) amplitude.
C) wavelength.
D) speed.
E) all of these

Question 63

Like a transverse wave, a longitudinal wave has

A) amplitude, frequency, wavelength, and speed
B) amplitude, wavelength, and speed.
C) wavelength, speed, and frequency.
D) amplitude, frequency, and wavelength.
E) amplitude, frequency, and speed.

Question 64

A tuning fork of frequency 200 hertz will resonate if a sound wave incident on it has a frequency of

A) 100 hertz.
B) 400 hertz.
C) either of 100 hertz or 400 hertz.
D) neither 100 hertz or 400 hertz.

Question 65

A dolphin perceives its environment by the sense of

A) sound.
B) sight.
C) both sight and sound.
D) neither sight or sound.

Question 66

When you tune a radio to a certain station, you match the frequency of the internal electrical circuit to the frequency of the wanted radio station. In so doing you are employing the principle of

A) beats.
B) forced vibrations.
C) reverberation.
D) resonance.
E) wave interference.

Question 67

Double the frequency of a sound and you halve its

A) wavelength.
B) amplitude.
C) speed.
D) all of these
E) none of these

Question 68

The speed of a sound wave in air depends on

A) its wavelength.
B) its frequency.
C) the air temperature.
D) All of the above choices are correct.
E) None of the above choices are correct.

Question 69

A sound wave is a

A) longitudinal wave.
B) standing wave.
C) shock wave.
D) transverse wave.
E) None of the above choices are correct.

Question 70

To say that one wave is out of phase with another is to say that the waves are

A) of different wavelengths.
B) out of step.
C) of different amplitudes.
D) of different frequencies.
E) all of these

Question 71

We are best at hearing

A) infrasonic sound.
B) ultrasonic sound.
C) both infrasonic and ultrasonic sounds.
D) None of the above choices are true.

Question 72

In the case of radio, which has the higher frequency?

A) Sound wave
B) Carrier wave
C) Neither. Both may be of the same frequency.

Question 73

In designing a music hall, an acoustical engineer deals mainly with

A) beats.
B) resonance.
C) forced vibrations.
D) wave interference.
E) modulation.

Question 74

The Doppler effect is characteristic of

A) light waves.
B) water waves.
C) sound waves.
D) all of the above choices
E) none of the above choices

Question 75

An explosion occurs 34 km away. Since sound travels at 340 m/s, the time it takes for the sound to reach you is

A) 0.1 second.
B) 10 seconds.
C) 1 second.
D) 20 seconds.
E) more than 20 seconds.

Question 76

The loudness of a sound is most closely related to its

A) speed.
B) wavelength.
C) frequency.
D) intensity.

Question 77

Resonance can be looked at as forced vibration with the

A) matching of wave amplitudes.
B) matching of constructive and destructive interference.
C) minimum beat frequency.
D) least amount of energy input.
E) maximum amount of energy input.

Question 78

A Doppler effect occurs when a source of sound moves

A) towards you.
B) away from you.
C) either towards you or away from you.
D) in a circle around you.

Question 79

Some of a wave's energy dissipates as heat. In time, this will reduce the wave's

A) wavelength.
B) speed.
C) period.
D) amplitude.
E) frequency.

Question 80

Some singers have been said to shatter a crystal chandelier shatter with their voice. This is a demonstration of

A) resonance.
B) an echo.
C) sound refraction.
D) beats.
E) interference.