Chapter 10 Test

Question 1

What factors affect the speed of sound?

Answer 1

the mediums:
-density
-elasticity
-composition
-temperature
-state of matter (solid, liquid, gas)

Question 2

What are the three parts of the ear?

Answer 2

outer ear
middle ear
inner ear

Question 3

What are the three ear bones?

Answer 3

malleus (hammer)
incus (anvil)
stapes (stirrup)

Question 4

What is intensity?

Answer 4

the amount of energy transferred by a sound wave through a certain area each second

Question 5

What is loudness?

Answer 5

the human perception of sound intensity

Question 6

What is frequency?

Answer 6

frequency is the measure of how many wavelengths pass a particular point each second

Question 7

What is pitch?

Answer 7

Pitch is the human perception of the frequency of a sound

Question 8

What is acoustics

Answer 8

the study of sound

Question 9

What is echo

Answer 9

a reflection of sound that arrives at the listener with a delay after the direct sound

Question 10

what is echolocation

Answer 10

the process of locating objects by emitting sounds and then interpreting the sound waves that are reflected from those objects

Question 11

What does SONAR stand for

Answer 11

SOund Navigation And Ranging

Question 12

why are sonars used

Answer 12

to locate objects or determine distance

Question 13

what is a sonar

Answer 13

a system that uses the reflection of underwater ultrasounds to locate objects or determine distances

Question 14

What is the normal frequency range of human hearing for young adults?

Answer 14

20Hz to 20,000Hz

Question 15

What are the factors needed for a room to cause an echo?

Answer 15

1. the time gap between the original sound and the reflected sound mus be at least 0.1 seconds
2. the distance between the original sound and the nearest wall must be at least 17.2 meters
3. minimal sound absorbing materials

Question 16

What are some uses for ultrasound?

Answer 16

-examine baby during pregnancy
-see organs in body
-break up kidney stones
-treat injury to soft tissue like muscle

Question 17

What is the speed of sound in air (0C)?

Answer 17

330 m/s

Question 18

What is the speed of sound in air (20C)?

Answer 18

340 m/s

Question 19

What is the speed of sound in cork

Answer 19

500 m/s

Question 20

What is the speed of sound in water (0C)?

Answer 20

1400 m/s

Question 21

What is the speed of sound in water (20C)?

Answer 21

1500 m/s

Question 22

What is the speed of sound in copper?

Answer 22

3600 m/s

Question 23

What is the speed of sound in bone?

Answer 23

4000 m/s

Question 24

What is the speed of sound in steel?

Answer 24

5800 m/s

Question 25

What receives the reflected sonar signal?

Answer 25

a hydrophone

Question 26

Why would someone use ultrasound instead of x-ray?

Answer 26

ultrasounds show movement
x-rays are bad for you

Question 27

What is persistence of hearing?

Answer 27

when you make a sound you are going to hear it for 0.1 seconds

Question 28

Sound waves are ____ waves

Answer 28

compressional/longitudinal
mechanical

Question 29

Sound waves travel by the process of ___

Answer 29

conduction

Question 30

What is amplitude related to on a longitudinal wave?

Answer 30

the density of the particles in the compressions and rarefactions

Question 31

sound waves with greater amplitudes carry ___ energy and therefore are ___

Answer 31

more
louder

Question 32

the intensity of a sound wave ___ as the wave spreads out from the source of the sound. Why?

Answer 32

decreases
-energy spreads out as the wave does
-sound energy converts to other forms

Question 33

What do sound waves’ energy usually convert to

Answer 33

thermal energy

Question 34

What materials are good at converting sound energy to other forms of energy?

Answer 34

soft thick curtains

Question 35

What is the unit used to measure sound intensity?

Answer 35

decibel (dB)

Question 36

What is intensity directly related to?

Answer 36

energy and loudness

Question 37

The frequency of a sound wave is directly related to ___

Answer 37

the pitch of a sound

Question 38

high pitch sound = ___ frequency

Answer 38

high

Question 39

What happens to the range of sound wave frequencies that you can hear as you age?

Answer 39

it decreases

Question 40

waves with frequencies above 20,000Hz are called ____

Answer 40

ultrasonic (ultrasound)

Question 41

waves with frequencies below 20Hz are called ____

Answer 41

Infrasonic (infrasound)

Question 42

What is the doppler effect

Answer 42

the change in the frequency of a wave due to relative motion of the wave source to the observer

Question 43

What are some different uses of sound waves?

Answer 43

medicine
fishing boats (detect schools of fish)
find sunken ships
building music halls and theaters
sound proofing rooms
finding oil or different minerals in the earth

Question 44

What uses echolocation?

Answer 44

bats and dolphins

Question 45

Ultrasound is sound with a frequency above ___Hz

Answer 45

20,000

Question 46

Why does sound travels faster in higher temperature mediums?

Answer 46

when the temperature of the medium increases, the particles in the medium move faster so they collide more often causing the sound waves to travel faster

Question 47

How does the ear work?

Answer 47

• Outer ear funnels sound into the eardrum where it vibrates
• In the middle ear the vibrations cause the lever system made out of the malleus, incus, and stapes to amplify the sound waves
  
  • the stirrup vibrates the oval window
• In the inner ear the vibrations from the oval window move the fluid in the cochlea (structure filled with liquid and tiny hairs) which moves the tiny hairs that are connected to the auditory nerve that converts the vibrations into electrical impulses