Conceptual Physics Ch 26 Test

In order for sound from a speaker to reach a listener, air near the speaker must travel to the listener.

false

A singer shattering a crystal glass with her voice is a demonstration of Echo Beats Resonance Interference?

resonance

The tacoma narrows bridge collapsed due to...

resonance

Sound waves are produced by )Radio stations )vibrating objects )soft objects?

vibrating objects

A 340Hz sound wave travels at 340 m/s in air, with a wavelength of ... 1 m 10 m 100 m

1 m

How many times more intense is a 80 dB sound than a 60 dB sound? 200 100 50

100

compared to a sound of 40 decibels, a sound of 60 decibels is? 20 times the intensity 100 times the intensity 200 times the intensity

100 times the intensity

compared to the threshold of hearing, a sound level of 30 decibels is? 10 times more intense 300 times more intense 30 times more intense 1000 times more intense

1000 times more intense

A general rule for finding the distance of lightening bolt is to count the number of seconds between seeing and hearing the bolt and divide by?

3

A sound wave that has a wavelength of 1 meters in room temp. air has a frequency of about... 340 Hz 680Hz 1020 Hz

340 Hz

A sound wave that has a wavelength of 1 meter in room-temperature air has a frequency of about 340Hz 680hz 1020hz None of these

340hz

You note a 2 second delay for an echo in a canyon. What is the distance to the wall of the canyon? 440hz 340hz 560hz

340hz

Two whistles produce sounds of wavelengths 3.4m and 3.3m. What is the beat frequency produced? .1Hz 1 Hz 2 Hz 3 Hz 4 Hz

4 Hz

How many times a minute will you be in step with a friend when you walk at 80 steps per minute and your friend walks at 75 steps per minutes? 155 80 75 5

5

Beats are produced when two tuning forks, one of frequency 240 Hz and the other frequency 246 Hz, are sounded together. The frequency of the beats is.. 6 Hz 12 Hz 240 Hz

6 Hz

The speed of sound in dry air at 20 degrees celcius is 340 m/s. How far away is a jet plane when you notice a 2 second delay between seeing the plane and hearin it? 6800m 680m 340m 40m

680 m

If you wished to produce a sound with a wavelength in air equal to the length of the room, 5m, what would be its frequency? 78hz 68hz 50hz 18hz

68hz

A tuning fork of frequency 200 Hz will resonate if a sound wave incident on it has a frequency of _____________? )100Hz )400Hz )Both 100 and 400

Both 100 and 400Hz

Sound waves can Interfere with one another so that no sound results true or false

False

Sound waves cannot travel in ______________. Air, water, vacuum, or all of the above?

a vacuum

Sound waves in air are a series of _______________? )Hi and low pressure regions, )periodic disturbances, )periodic conversion and rarefractions, )all of the above

all of the above

You are water skiing on a lake, and you are being pulled by a noisy motorboat. Another motorboat is speeding through the water a bit ahead of your boat so that rarefactions from its motor hit you when compressions from your boats motor hit you. you hear....

almost nothing due to destructive interference

Resonance occurs when...

an object is forced to vibrate at its natural frequency

When the handle of a tuning fork is held solidly against a table, the sound becomes louder and the length of time the fork vibrates Longer Shorter The same?

becomes shorter

Noise cancelling earphones are an example of

destructive interference

a pulse of compressed air that is part of a sound wave is a rarefaction

false

sound can travel through solids. liquids, gases, and even a vacuum.

false

the word "pitch" refers to the period of a sound wave

false

The speed of a sound wave depends on ________________. )Frequency )Wavelength )Air temp

frequency

Beats can be heard when two tuning forks.... )Are sounded together )have almost same frequency and are sounded together?

have almost the same frequency and are sounded together

In which one of the following does sound travel the fastest? Steam Water Ice

ice

The phenomenon of beats results from sound Refractions Reflection Interference All of the above

interference

If you are standing equally distant from two television sets that are emitting the exact same sound waves, the sound...

is louder because the waves constructively interfere.

A sound wave is a ________________. )Transverse wave )Standing wave )Longitudinal wave

longitudinal wave

If the sounding board were left out of a music box, the music box would make the same sound or not a sound at all?

not sound at all

Compared to the speed of light, sound travels Faster slower or about the same?

slower

Which of the following would be most likely to transmit sound with the highest speed? )Steel bridge )Water in a pool )Wood cabinet

steel in a bridge

almost everything that exists has a natural frequency.

true

even a steel bridge can collapse because of resonance.

true

if you strike a tuning fork and hold it on a table, the sound becomes relatively loud.

true

when an object is disturbed slightly and then left alone, its vibrates at its natural frequency.

true

when an object is forced to vibrate at its natural frequency, its vibration amplitude increases.

true

when an object is forced to vibrate at its natural frequency, resonance occurs.

true

Sound travels faster in air if the air is warm, cold or neither?

warm