General Knowledge - Physics - Discussion

Can someone explain it in depth?

You are right. I agree @Cm Prasad.

Name some animals which hear below 20Hz.

Which frequency makes man's ear dum?

@Tracy.

20HZ - 20000HZ(sometimes 16000 HZ).

How much HZ is needed for a human being?

Because man cannot hear sound less than 20 Hz.

The human beings cannot listen to the sound which is below 20Hz. Only some type of animals can hear it like bat's.

@Nishtha you are wrong.

Infrasonic - frequency less than 20 hz (can not be hear).

Visible light - frequency 20 hz to 20, 000 hz (can be hear).

Ultrasonic - more than 20, 000 (can not be hear).

NOTE - all three forms relate with frequency but supersonic not.

Supersonic relates with velocity.

Hence supersonic - the sound wave having speed more than 332 meter/second (velocity of sound in air).

Supersonic jet planes named on property because they have speed more than 332 m/s.

Infrasonic. The relevance of this particular frequency is that it is the lower limit of hearing the normal people.