Chap 10

Question 1

Sound is:

Answer 1

a form of energy caused by vibration

Question 2

Characteristics of sound waves

Answer 2

• requires a medium to propagate
  -propagate at diff speeds in diff medium
• can be reflected and absorbed

Question 3

Sound can propagate through ______, ____ and ____ but not through ____

Answer 3

can propagate through:
- liquid, solid and gas
Cannot propagate through:
- vacuum

Question 4

how does waves work

Answer 4

• when a surface of the object vibrate, air molecules near the surface will also vibrate and collide w the air molecules nearby
• this vibration is transferred from one molecule to another molecule beside it in the form of waves

Question 5

sound is transferred _________ in solids

Answer 5

very rapidly

Question 6

sound is transferred __________ in liquids

Answer 6

less rapidly

Question 7

sound is transferred _________ in liquids

Answer 7

very slowly

Question 8

Sound can be ____________ and _____________ when it hits the surface of an object

Answer 8

• reflected
• absorbed

Question 9

the amount of sound reflected or absorbed depends on:

Answer 9

• depends on the surface of the object

Question 10

What are good sound reflectors

Answer 10

hard and smooth surfaces

Question 11

why can our ears differentiate the sounds that r heard

Answer 11

• bcuz of the different strengths n pitches in sounds

Question 12

the strength or loudness of sound produced depends on :

Answer 12

the amplitude of the sound wave

Question 13

pitch of sound depends on

Answer 13

the frequency of the sound produced

Question 14

frequency is measured in the unit of

Answer 14

hertz (Hz)

Question 15

reflection of sound waves produces

Answer 15

echo

Question 16

Elaborate on echo

Answer 16

• produced when sound waves r reflected from a hard surface to the listener
• sounds the same as original sound but takes some time to reach the listener’s ears
  -can be heard in enclosed places

Question 17

Elaborate on Ultrasound

Answer 17

• a type of sound wave with a frequency of more than 20,000 Hz
• cannot be heard by humans but can be heard by animals such as bats that use it for navigation

Question 18

the frequency of sound that can be detected by humans is within the range of

Answer 18

20 Hz to 20,000 Hz