Sound
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!