1
00:00:05,870 --> 00:00:22,870
So we got sound. This unit is called sound. Let it hit. Yesterday you started coloring your first page in the notebook and with the vocabulary, right? Okay. Now, sound. We start with sound today.

2
00:00:22,870 --> 00:00:32,109
when an object vibrates it produces sound waves these waves travel through a solid medium liquid

3
00:00:32,109 --> 00:00:39,469
or gas to our ears so we can hear so sound is produced when an object vibrates like for

4
00:00:39,469 --> 00:00:52,250
example our throat is vibrating so it produces sound waves now big vibrations amount to loud

5
00:00:52,250 --> 00:01:02,320
sounds. However, small vibrations are equivalent to quiet sounds. Sound waves

6
00:01:02,320 --> 00:01:10,000
can travel through a vacuum. What is a vacuum? El vacío, un vacío. Okay, if

7
00:01:10,000 --> 00:01:17,379
there's no air, no liquid, no gas, sounds can travel. For example, space is a giant

8
00:01:17,379 --> 00:01:24,159
empty vacuum with no air and here you got the picture of these astronauts here

9
00:01:24,159 --> 00:01:28,200
is it and I can't hear you and you did something similar in your book I think

10
00:01:28,200 --> 00:01:37,650
but astronauts can hear themselves through the space now important sound

11
00:01:37,650 --> 00:01:44,209
moves four times faster through the water than through the air okay here you

12
00:01:44,209 --> 00:01:52,010
got a representation of how sound can travel in those waves. Look at the

13
00:01:52,010 --> 00:01:57,230
dolphins and they can communicate with each other and some animals that live in

14
00:01:57,230 --> 00:02:04,269
the sea. Well to finish let's sign up with this small activity. It's very easy

15
00:02:04,269 --> 00:02:12,710
you'll see. When an object vibrates it produces sound waves. These waves travel

16
00:02:12,710 --> 00:02:19,789
through what is solid liquid gas through a medium to our ears so we can hear them.

17
00:02:19,789 --> 00:02:26,870
We perceive large vibrations, remember large vibrations, as loud sounds. However

18
00:02:26,870 --> 00:02:34,150
small vibrations we perceive it as quiet sounds. Good. Sound waves can only travel

19
00:02:34,150 --> 00:02:41,090
through a medium such as air. They cannot travel through this word that we learned

20
00:02:41,090 --> 00:02:48,150
today vacuum very good and what is a giant empty vacuum with no air with

21
00:02:48,150 --> 00:02:56,030
example I gave you space that's it very good well so this is sound please if you

22
00:02:56,030 --> 00:03:02,509
have any question ask me don't forget but well also we got jet-sea tomorrow so

23
00:03:02,509 --> 00:03:08,189
you can ask me anything you want all right goodbye