Sound waves

Sounds are

is sound a mechanical wave ?

Sounds require

• medium to propagate

• solid and liquid to propagate

• gas to propagate

• none

Sound propagates in vacuum.

• Yes

• No

• I don't know

Sound receivers are organs or instruments that are sensitive to sound vibrations.

• True

• False

we only hear sounds with audible frequencies between

• 10 Hz and 10000 HZ

• 200 Hz and 20000 HZ

• 20 Hz and 20000 Hz

Infrasounds are

• below 20 Hz

• above 20 Hz

• 20000 Hz

ultrasouns are above

• 20 HZ

• 20000Hz

• 10000Hz

can we hear infrasouunds or ultrasounds ?

give examples or ultrasounds and infrasounds.