Physics chapter 10

Wave interference occurs for

-light waves. -sound waves. -water waves. -*all of the above

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

0.1 S

What beat frequency is produced when a 240-Hz and a 246-Hz tuning fork are sounded together?

6 Hz

Sound waves cannot travel in

a vacuum

A standing wave occurs when

a wave reflects upon itself

The vibrations of a longitudinal wave move in a direction

along the direction of wave travel.

A sonic boom can NOT be produced by

an aircraft flying slower than the speed of sound.

The reflection of sound is

an echo

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

at its natural frequency.

The vibrations of a transverse wave move in a direction

at right angles to the direction of wave travel.

For light, a red shift indicates the light source moves

away from you

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

downward

What moves from place to place in wave motion is

energy

Frequency = 1/period A pendulum swings to and fro every 2.6 s . Find its frequency of swing.

f = 0.38 Hz

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

frequency

Sound travels fastest in

ice

The phenomenon of beats results from sound

interference

A sound wave is a

longitudinal wave.

Compressions and rarefactions are characteristic of

longitudinal waves

Double the frequency of sound and you also double its

none of the above

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

one wavelength.

Which doesn't belong to the same family?

radio waves

Reverberation is a case of

re-echoed sound.

Some singers are able to shatter a crystal chandelier with their voice, which illustrates

resonance

Troops break step when marching across a bridge to prevent

resonance

When you tune a radio to a certain station, you match the frequency of the internal electrical circuit to the frequency of that radio station, which illustrates

resonance

A bass fiddle is louder than a harp because of its

sounding board

The explanation for all types of refraction involves a change in

speed

A compression is a squash and a rarefaction is a

stretch

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

tend to be refracted downward.

The speed of a sound wave in air depends on

the air temperature

A Doppler effect occurs when a source of sound moves

toward you

The medium in which a wave travels

transmits the wave

Sound waves can interfere with one another so that no sound is produced.

true

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

upward

Wave speed = frequency × wavelength = fλ Find a wave speed of a certain 1.1-m-long wave with a frequency of 2.5 Hz .

v = 2.8 m/s

Wave speed = frequency × wavelength = fλ A tuning fork produces a sound with a frequency of 256 Hz and a wavelength in air of 1.33 m. Find the speed of sound in the vicinity of the fork.

v = 340 m/s

The source of all sounds is something that is

vibrating

Sound travels faster when the air is

warm

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

wave interference.

The highest frequency sound humans can hear is about 20,000 Hz. What is the wavelength of sound in air at this frequency? What is the wavelength of the lowest sounds we can hear, about 20 Hz?

λ = 1.7 cm λ = 17 m

For years, marine scientists were mystified by sound waves detected by underwater microphones in the Pacific Ocean. These so-called T waves were among the purest sounds in nature. Eventually the researchers traced the source to underwater volcanoes whose rising columns of bubbles resonated like organ pipes. A typical T wave has a frequency of 7 Hz. Knowing that the speed of sound in seawater is 1530 m/s, find the wavelength of a T wave.

λ = 219 m

The natural frequency of an object depends on its

-size and shape. -elasticity. -*both

The Doppler effect is characteristic of

-sound waves. -water waves. -light waves. -*all of the above

A dolphin perceives its environment by the sense of

-sound. -sight. -*both

A wave is a vibration in

-space. -time. -*both

A Doppler effect occurs when a source of sound moves

-toward you. -away from you. -*either

Sound energy that is not reflected is

-transmitted. -absorbed. -*either or both

In perceiving its environment, a dolphin makes use of

-ultrasound. -the Doppler effect. -echoes. -*all of the above

Refraction of sound can occur in

-water. -air. -*both

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

.5 Hz

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

.5 Hz

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

1 m

The frequency of the second hand on a clock is

1/60 Hz.

A wave having a frequency of 1000 Hz vibrates at

1000 cycles per second.

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

101,000,000

Suppose you sound a 1056-Hz tuning fork when you strike a note on the piano and hear 2 beats/second. You tighten the piano string very slightly and now hear 3 beats/second. What is the frequency of the piano string?

1059 Hz

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?

2 Hz

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?

2 m/s

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

2 s

The range of human hearing is about

20 Hz - 20,000 Hz.

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?

20 m/s

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

200 Hz

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

2295 m

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

3

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

3 m

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?

3 m/s

Two tuning forks produce sounds of wavelengths 3.4 m and 3.3 m. What beat frequency is produced?

3.0 Hz

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

3.0 m

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

340 m

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

4.0 s

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

50 Hz with a period of 1/50 s.

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

6 m/s

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

60 Hz and it travels at 30 m/s.

The period of the second hand on a clock is

60 s

The siren of a fire engine is heard in three situations: when the fire engine is traveling (a) toward the listener at 60 km/h , (b) toward the listener at 40 km/h , and (c) away from the listener at 30 km/h . Rank the pitches heard, from highest to lowest.

A, B, C

Rank the speed of sound through the following media from fastest to slowest: (a) air, (b) steel, (c) water

B, C, A

A railroad locomotive is at rest with its whistle shrieking, and then it starts moving toward you. Does the frequency that you hear increase, decrease, or stay the same?

The frequency increases

How about the speed of sound in the air between you and the locomotive?

The speed is unchanged.

How about the wavelength reaching your ear?

The wavelength decreases.

A shock wave is produced when the speed of an object

exceeds the speed of sound in air.

A bow wave is produced in water when the speed of an object

exceeds the speed of waves in water.

Compressions and rarefactions normally travel

in the same direction in a wave.

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

increased

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

is half

A wave barrier is produced in water when the speed of an object

matches the speed of waves in water.

A node is a position of

minimum amplitude

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

more than 20 s.

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

not enough information

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

period

A sound source of high frequency emits a high

pitch

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

shortens

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

shorter

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

shower

The object with the natural frequency of higher pitch is a

small bell

Which of the following is a longitudinal wave?

sound

Which of the following is not a transverse wave?

sound

In a longitudinal wave, the compressions and rarefactions travel in

the same direction.

The source of all wave motion is a

vibrating object

A wiggle in time is a

vibration