Chapter 13 (sound)

Question 1

How are sounds produced?

Answer 1

By objects that are vibrating.

Question 2

Does sound need medium?

Answer 2

Yes

Question 3

Sound travel the fastest passing through which medium?

Answer 3

solid

Question 4

What is speed of sound in air?

Answer 4

330m/s

Question 5

What is the relationship between speed of the sound and temperature?

Answer 5

Directly proportional

Question 6

Sound hit _____ in our ear, so that we can hear.

Answer 6

Ear drum

Question 7

Which kind of waves need medium?

Answer 7

Mechanical

Question 8

Is sound conversed or longitudinal wave?

Answer 8

Longitudinal wave

Question 9

What is echo?

Answer 9

Reflection of sound

Question 10

What is audible range?

Answer 10

Range of sound frequencies that we can hear.

Question 11

Audible range become narrower as we _____.

Answer 11

Get older

Question 12

What can you used to produce sound at different ferquencies?

Answer 12

~ signal generator
~ Loudspeaker

Question 13

What is the audible range for human?

Answer 13

20Hz —–> 2000Hz

Question 14

What do we call sound lower than 20Hz?

Answer 14

Infrasound

Question 15

What do we call sound higher than 2000Hz?

Answer 15

Ultrasound

Question 16

Give an example of one animal that use infrasound and ultrasound to communicate?

Answer 16

Ultrasound - Dolphin
Infrasound - Elephant