Sound

Watch Sound - Edu-Primes on Dailymotion

Transcript

00:00Hey there! Enjoyed those sounds?

00:26Well, then let's talk about sound today!

00:29ZOOM IN!

00:31Sound is a wave or vibration that travels through three states of matter.

00:37Solid, liquid and gas.

00:41And of course, it is something that can be heard.

00:44But, have you ever wondered, how does sound travel?

00:49It's simple.

00:51It all starts with a mechanical movement.

00:54Like pouring hot chocolate in a mug.

00:58Clapping your hands or hitting a gong.

01:02So, when you hit a gong, there's a movement which causes some vibrations in the molecules.

01:10Which in turn, causes the other molecules around them to vibrate.

01:16And these vibrations from one molecule to the other help sound to travel.

01:28Hmm, you couldn't hear me, right?

01:33Well, because I was in vacuum.

01:36In spaces, where there is just vacuum and no matter.

01:41Sound will not travel, because there won't be any molecules to vibrate.

01:49Frequency is an important measure of sound.

01:54When there are more number of sound waves passing through a fixed place at a given time.

01:59It means that the frequency is high.

02:03When the number of waves become less, we hear low frequency sound waves.

02:10The human ear is capable of detecting frequencies between 20 Hz to 20,000 Hz.

02:19Any frequency above or below that is inaudible to the human ear.

02:25Higher frequency sound waves will give us a higher pitch.

02:30Hmm, take a guitar and play the heavier string.

02:35Hearing the buzz?

02:37Now, play the thinner string.

02:40Isn't there a difference in sound?

02:43Well, that's the difference in pitch.

02:47The loudness of sound is measured in volume.

02:52And to quantify volume, we use decibels.

02:56Here is an example of volume.

02:58Can you hear me now?

03:04Trivia Time!

03:06Sound waves can bend around corners and obstacles.

03:11Any sound with a frequency below 20 Hz is called infrasound.

03:17And any sound with a frequency above 20,000 Hz is known as ultrasound.

03:25So, this is me zooming out.

03:28Tune in next time for more fun facts!