20

Question 1

Pitch

Answer 1

The highness or lowness of a tone: related to wave frequency

Question 2

Infrasonic/Ultrasonic

Answer 2

Too low or high to be heard by the human ear. Below 20, above 20,000

Question 3

Reverbation

Answer 3

Persistence of sound, as in an echo, due to multiple reflections

Question 4

Natural frequency

Answer 4

The frequency at which an elastic object tends to vibrate when it is disturbed and the disturbing force is removed. Depends on elasticity and shape of object.

Question 5

Sound

Answer 5

Waves produced by the vibrations of matter (strings, reeds, vocal cords)

Question 6

Sound waves (3)

Answer 6

Are vibration made of compressions and rarefactions. Are longitudinal waves. Require a medium (solid/liquid/gas)

Question 7

Wavelength of sound

Answer 7

Distance between succesive compressions or rarefactions.

Question 8

What is the wave frequency of sound produced by a 220 hz tuning fork?

Answer 8

220 Hz

Question 9

Most sound is transmitted through ____, but any _____ substance can transmit sound.

Answer 9

Air, Elastic

Question 10

Sound travels __ times faster in water and ___ faster in steel than air.

Answer 10

4, 15

Question 11

Compression

Answer 11

A pulse of compressed air

Question 12

Rarefaction

Answer 12

zone of lower pressure

Question 13

Do compressions and rearefactions in a sound wave travel in the same or opposite directions?

Answer 13

Same

Question 14

What is the approximate distance of a thunderstorm when you note a 3s delay between the flash of lightening and sound of the thunder?

Answer 14

Assuming speed of sound in air is about 340 m/s, 1020m.

Question 15

How much energy does sound require?

Answer 15

Very small - 10 million people talking would power a small flashlight.

Question 16

What travels farther - low or high freq?

Answer 16

High freq wave transform (lost as heat) more rapidly, so low freq travels farther.

Question 17

Echo

Answer 17

Reflection of sound, many times

Question 18

Refraction

Answer 18

When sound waves continue through a medium and bend (caused by changes in speed). Sound waves bend when parts of the wavefronts travel at different speeds. Wind, uneven temp, altitude can cause this.

Question 19

Resonance

Answer 19

When the freq of forced vibrations on an object matches the object’s natural frequency and a dramatic increase in amplitude occurs. Tacoma narrows bridge…

Question 20

A depth-sounding vessel surveying the ocean with ultrasonic sound that travels and average of 1530 m/s. How deep is the water is the delay of the echo is 2 sec?

Answer 20

1530 - 1 sec down, 1 up

Question 21

How do sound cancelling headphones work?

Answer 21

Destructive sound interference. 180 difference

Question 22

Beat

Answer 22

Periodic variation in the loudness of sound. Happens when two tones of slightly different frequency are sounded together and a fluctuation in the loudness of the combined sound causes loud/faint/loud/faint.

Question 23

What is the beat frequency when a 262 Hz tuning fork and a 266 Hz tuning fork are sounded together?

Answer 23

The ear will hear 264 Hz which will beat at 4 Hz.

Question 24

What is the relationship betweenfrequencyandpitch?

Answer 24

Pitch is the human perception of sound frequency.

Question 25

What factors does the speed of sound depend upon? What are some factors that it does not depend upon?

Answer 25

It depends on temperature and humidity, not on loudness and frequency.

Question 26

What is the cause of refraction?

Answer 26

Different speeds of sound in a medium Sound waves bend when parts of the wavefront travel at different speeds. Uneven wind, temps. Why thunder is not heard from far away lightening.

Question 27

What is the result of a mirror image of a sound signal combining with the sound itself?

Answer 27

The sound is cancelled when added to its mirror image.

Question 28

Speed of sound depends on:

Answer 28

Depends on wind, temp, humidity. Dry air is 330 m/s, slightly faster in water vapor, warm air faster than cold. Each degree above 0°C ↑ speed of sound by .6 m/s

Question 29

Relative to solids and liquids, how does air rank as a conductor of sound?

Answer 29

Relative to solids and liquids, air is a poor conductor of sound.

Question 30

What beat frequency will occur when a 370-Hz and a 374-Hz sound source are sounded together?

Answer 30

4 hz

Question 31

A cat can hear sound frequencies up to 70,000 Hz. Bats send and receive ultra-high-frequency squeaks up to 120,000 Hz. Which hears sound of shorter wavelengths, cats or bats?

Answer 31

The shorter wavelengths are heard by bats.