Deck 10: Waves and Sound

Question 1

When we consider how frequently a pendulum swings to and fro we're talking about its

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

Answer 1

A

Question 2

The period of the second hand on a clock is

A)1 s.
B)1/60 s.
C)60 s.
D)3600 s.
E)12 h.

Answer 2

C

Question 3

The frequency of the second hand on a clock is

A)1 Hz.
B)1/60 Hz.
C)60 Hz.

Answer 3

B

Question 4

A 60 vibration per second wave travels 30 m in 1 s. Its frequency is

A)30 Hz and it travels at 60 m/s.
B)60 Hz and it travels at 30 m/s.
C)neither

Question 5

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

A)doubles.
B)is half.
C)is one quarter.

Question 6

When we consider the time taken for a pendulum to swing to and fro we're talking about the pendulum's

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

Question 7

A wiggle in time is a

A)vibration.
B)wave.
C)both
D)neither

Question 8

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

A)less than 101,000,000
B)101,000,000
C)more than 101,000,00

Question 9

A child swings to and fro on a playground swing. If the child stands on the swing rather than sitting on it, the time for a to-and-fro swing is

A)lengthened.
B)shortened.
C)unchanged.

Question 10

If the frequency of a certain wave is 10 Hz, its period is

A)0.1 s.
B)10 s.
C)100 s.
D)none of the above

Question 11

The pendulum with the greatest frequency has the

A)shortest period.
B)shortest length.
C)both
D)neither

Question 12

A wave is a vibration in

A)space.
B)time.
C)both
D)neither

Question 13

A wave having a frequency of 1000 Hz vibrates at

A)less than 1000 cycles per second.
B)1000 cycles per second.
C)more than 1000 cycles per second.

Question 14

What is the relationship between wave frequency and period? What is the period, in seconds, that corresponds to each of the following frequencies: (a)10 Hz, (b)0.2 Hz, (c)60 Hz?

Question 15

When we consider the distance a pendulum swings to and fro we're talking about the pendulum's

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

Question 16

A weight suspended from a spring bobs up and down one complete cycle every 2 s. Its frequency is

A)0.5 Hz.
B)1 Hz.
C)2 Hz.
D)none of the above

Question 17

A weight suspended from a spring bobs up and down one complete cycle every 2 s. Its period is

A)0.5 s.
B)1 s.
C)2 s.
D)none of the above

Question 18

A mass on the end of a spring bobs up and down 1 complete cycle every 2 s. Its frequency is

A)0.5 Hz.
B)2 Hz.
C)neither

Question 19

In Europe an electric razor completes 50 vibrations in 1 s. The frequency of these vibrations is

A)50 Hz with a period of 1/50 s.
B)1/50 Hz with a period of 50 s.
C)50 Hz with a period of 50 s.
D)1/50 Hz with a period of 1/50 s.

Question 20

When a pendulum clock at sea level is placed at the top of a high mountain, it will

A)gain time.
B)lose time.
C)neither

Question 21

The vibrations of a transverse wave move in a direction

A)along the direction of wave travel.
B)at right angles to the direction of wave travel.
C)opposite to wave travel.

Question 22

A floating leaf oscillates up and down 2 complete cycles in 1 s as a water wave of wavelength 10 m passes by. What is the wave's speed?

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

Question 23

What moves from place to place in wave motion is

A)energy.
B)momentum.
C)pressure.
D)matter.

Question 24

In a longitudinal wave, the compressions and rarefactions travel in

A)the same direction.
B)opposite directions.
C)neither

Question 25

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

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

Question 26

The source of all wave motion is a

A)wave pattern.
B)harmonic object.
C)vibrating object.
D)region of variable high and low pressure.
E)none of the above

Question 27

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 m long. What is the speed of the wave?

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

Question 28

The medium in which a wave travels

A)moves along with the wave.
B)transmits the wave.
C)inhibits the wave.
D)reflects the wave.

Question 29

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

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

Question 30

A boat at anchor is rocked by waves whose crests are 40 m apart and with wave speed 10 m/s. These waves reach the boat once every

A)400 s.
B)30 s.
C)4.0 s.
D)0.25 s.

Question 31

A floating leaf oscillates up and down two complete cycles each 1 s as a water wave passes by. What is the wave's frequency?

A)0.5 Hz
B)1 Hz
C)2 Hz
D)3 Hz
E)6 Hz

Question 32

A wave travels an average distance of 1 m in 1 s with a frequency of 1 Hz. Its amplitude is

A)less than 1 m.
B)1 m.
C)more than 1 m.
D)not enough information

Question 33

The vibrations of a longitudinal wave move in a direction

A)along the direction of wave travel.
B)at right angles to the direction of wave travel.
C)opposite to wave travel.

Question 34

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

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

Question 35

Which of the following is not a transverse wave?

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

Question 36

Show the relationship between wave speed and wave frequency. If the speed of a longitudinal wave is 340 m/s and the frequency is 1000 Hz, what is the wavelength of the wave?

Question 37

A wave oscillates up and down two complete cycles each 1 s. If the wave travels an average distance of 6 m in 1 s, its wavelength is

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

Question 38

A wave travels an average distance of 6 m in 1 s. What is the wave's velocity?

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

Question 39

Which of the following is a longitudinal wave?

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

Question 40

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

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

Question 41

Our ears are best at hearing

A)infrasonic sound.
B)ultrasonic sound.
C)both
D)neither

Question 42

Sound travels faster when the air is

A)warm.
B)cold.
C)neither

Question 43

Sound waves cannot travel in

A)air.
B)water.
C)steel.
D)a vacuum.

Question 44

The source of all sounds is something that is

A)accelerating.
B)moving.
C)vibrating.
D)undergoing simple harmonic motion.

Question 45

The speed of a sound wave in air depends on

A)its frequency.
B)its wavelength.
C)the air temperature.
D)all of the above
E)none of the above

Question 46

Sound travels faster in

A)air.
B)water.
C)steel.
D)a vacuum.
E)same in each

Question 47

Distinguish between a transverse wave and a longitudinal wave. Give examples of each.

Question 48

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

A)1 m.
B)10 m.
C)100 m.
D)1000 m.
E)none of the above

Question 49

A sound source of high frequency emits a high

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

Question 50

Sound travels fastest in

A)water vapor
B)water
C)ice

Question 51

A sound wave is a

A)longitudinal wave.
B)transverse wave.
C)standing wave.
D)shock wave.
E)none of the above

Question 52

What is an echo, and why is it weaker than the original sound?

Question 53

A compression is a squash and a rarefaction is a

A)crunch.
B)reverse tension.
C)stretch.

Question 54

The reflection of sound is

A)reverberation.
B)an echo.
C)bouncing waves.

Question 55

An explosion occurs 34 km away. For sound that travels at 340 m/s, you'll hear the explosion in

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

Question 56

The range of human hearing is about

A)10 Hz - 10,000 Hz.
B)20 Hz - 20,000 Hz.
C)40 Hz - 40,000 Hz.
D)all of the above, depending on the person

Question 57

Compressions and rarefactions normally travel

A)at right angles to the wave.
B)in the same direction in a wave.
C)in opposite directions in a wave.
D)none of the above

Question 58

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 the above

Question 59

Compressions and rarefactions are characteristic of

A)longitudinal waves.
B)transverse waves.
C)both
D)neither

Question 60

Double the frequency of sound and you also double its

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

Question 61

Reverberation is a phenomenon you would likely to hear if you sing in the

A)shower.
B)desert.
C)tundra.

Question 62

Refraction of sound can occur in

A)air.
B)water.
C)both
D)neither

Question 63

While at a concert, a wind blows directly from the orchestra toward you. The wavelength of the sound you hear is

A)decreased.
B)increased.
C)neither

Question 64

When sound travels faster higher above ground level than it does closer to the ground, sound bends

A)upward.
B)downward.
C)neither

Question 65

Ultrasonic sound that travels at 1530 m/s in ocean water is bounced off the ocean floor and returns to the ship above. If the round trip takes 3 s, the depth of the water is

A)1530 m.
B)2295 m.
C)3060 m.
D)4590 m.

Question 66

A dolphin perceives its environment by the sense of

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

Question 67

On days when the air nearest the ground is colder than air above, sound waves

A)tend to be refracted upward.
B)tend to be refracted downward.
C)travel without refraction.

Question 68

Reverberation is a case of

A)sound interference.
B)forced vibrations.
C)re-echoed sound.
D)resonance.
E)none of the above

Question 69

Resonance occurs when a 200-Hz tuning fork encounters a sound wave with a frequency of

A)150 Hz.
B)200 Hz.
C)300 Hz.
D)any of the above
E)none of the above

Question 70

In designing a music hall, an acoustical engineer is concerned with

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

Question 71

A bat chirps to locate a tasty lunch. The chirp travels at 340 m/s and its echo is heard 1 s after the chirp. Distance to the lunch is

A)85 m.
B)170 m.
C)340 m.

Question 72

Sound energy that is not reflected is

A)transmitted.
B)absorbed.
C)either or both

Question 73

When sound travels faster at ground level than higher in the air, sound tends to bend

A)upward.
B)downward.
C)neither

Question 74

The natural frequency of an object depends on its

A)elasticity.
B)size and shape.
C)both
D)neither

Question 75

Sound refraction depends on the speed of sound being

A)constant.
B)variable.
C)proportional to frequency.
D)inversely proportional to wavelength.
E)none of the above

Question 76

The least amount of energy is required to produce forced vibration in an object

A)below its natural frequency.
B)at its natural frequency.
C)above its natural frequency.

Question 77

The explanation for all types of refraction involves a change in

A)frequency.
B)period.
C)speed.
D)all of the above
E)none of the above

Question 78

The object with the natural frequency of higher pitch is a

A)small bell.
B)large bell.
C)either
D)neither

Question 79

While at a concert, a wind blows directly from the orchestra toward you. You hear the average frequencies of sound

A)decreased.
B)increased.
C)neither

Question 80

While at a concert, a wind blows directly from the orchestra toward you. The speed of the sound you hear is

A)decreased.
B)increased.
C)neither.