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Heat and Light (II)

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Subido el 15 de abril de 2020 por Cp castilla alcobendas

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Hello everyone, this is Kori and today we are going to continue talking about heat and light. 00:00:00
First we will discuss heat and matter. Heat is a form of energy that passes from a hotter object 00:00:10
to a colder one and matter is something that takes up space and has mass. Things like air, 00:00:25
Air, water, rocks, and people are all examples of matter. 00:00:33
If matter absorbs heat, its temperature increases. 00:00:41
It gets warmer. 00:00:47
So when you cook food, your food absorbs heat. 00:00:52
It takes in heat. 00:00:56
The temperature of your food increases 00:00:58
and the food gets warmer. 00:01:01
If matter emits heat, 00:01:05
temperature decreases, it cools down. So when an animal gives off or emits heat 00:01:08
its temperature decreases. The temperature goes down which means it's 00:01:18
cooling down and the animal is getting colder as it emits heat. If two objects 00:01:25
with different temperatures come into contact, heat transfers from the 00:01:35
hotter object to the colder one and they are the same temperature. So we are going 00:01:44
to see this in these pictures here. First let's look at the one on the left. In 00:01:53
In this picture, you can see that a glass of hot water is put into a pan of colder water. 00:01:59
The thermometer tells us that the temperature of the glass of water is 90 degrees Celsius. 00:02:10
The temperature of the water in the pan is 40 degrees Celsius. 00:02:19
obvious. These objects have different temperatures. Can you guess which way the heat will transfer? 00:02:25
Remember, when objects are in direct contact, meaning they are right next to each other, 00:02:38
heat moves from the hotter one to the colder one. In this example, heat would be transferred 00:02:46
from the 90 degree cup of water to the 40 degree pan of water. 00:02:54
Eventually the water in the cup and the water in the pan will be the same temperature. 00:03:04
We can see this in the second picture. 00:03:13
The thermometer tells us that the temperature of the water in the cup is 60 degrees Celsius. 00:03:19
and the water in the pan is also 60 degrees celsius. They are now the same temperature. 00:03:28
If matter gets hot, it usually gets bigger. It expands. We see this when we're baking 00:03:41
muffins or cakes or bread. A cake will get bigger when it's cooked. It expands as it gets warmer. 00:03:52
If matter cools down, it usually gets smaller. It contracts. So here's a tip to help you remember 00:04:05
this. When you are cold, you typically bring your arms in close to your body and you make yourself 00:04:15
smaller. As matter gets colder, it contracts and gets smaller, just like how you make yourself 00:04:21
smaller when you're feeling cold. Water, however, is a special case. Water does the opposite. 00:04:30
Water increases in size when it freezes. So water gets bigger when it freezes. This is different 00:04:42
than other types of matter. Other types of matter typically get smaller when 00:04:51
they get colder. Conducting materials let heat pass through them. Conducting 00:05:00
materials are called conductors. Many types of metals are good conductors. This 00:05:13
is why we cook with metal pans. Non-conducting materials do not let heat pass through them. 00:05:22
Non-conducting materials are called insulators. The tires or wheels on cars are made of rubber, 00:05:36
which is an insulator. Plastic and wood are also insulators. When you cook, you probably stir your 00:05:45
food with a spoon or spatula made of an insulator. This keeps your hands from getting too hot. 00:05:54
If you tried to cook with a conducting material to stir your food, the spoon would get really hot. 00:06:05
The heat would transfer from your stove, to the pot, to the spoon, 00:06:16
and then to your hand, and your hand would get burned. Ouch. So if you use an 00:06:23
insulator to stir your food when you're cooking, the insulator will protect you 00:06:31
from getting burned because heat cannot pass through an insulator. Now we are 00:06:39
going to talk about the three states of matter. Solid, liquid, and gas. Solid 00:06:54
matter is rigid. It is not flexible and it does not move around. Solid matter has 00:07:03
a fixed shape and a fixed volume. It stays as it is. 00:07:11
Solids cannot be squashed. You probably see lots of examples of solids around 00:07:19
you now. Solids are things like a chair, a rock, a table, or a car. Liquid matter is 00:07:26
not rigid. It has no fixed shape. Liquids take on the shape of the container they 00:07:37
in. Liquids have a fixed volume. This means that they always take up the same 00:07:45
amount of space. Liquids cannot be squashed. Liquids include things like 00:07:55
water, juice, or coffee. Gas is not rigid. It does not have a fixed shape and gas 00:08:03
does not have a fixed volume. Gas can be squashed. Gases move around freely. You 00:08:17
can put your hand through a gas and not feel anything. There are gases in the air 00:08:27
that we breathe and in the steam coming off of soup or tea. Matter can change 00:08:32
state. When a solid changes into a liquid, we call that melting. When a liquid 00:08:46
changes into a gas, we call that evaporation. When a solid changes into a 00:09:00
gas, we call that sublimation. Here we have a diagram showing you how matter 00:09:11
can change state. When the arrows are moving to the right from solid, liquid, to 00:09:26
gas, the matter is getting warmer. When the arrows are moving to the left from 00:09:35
gas, liquid, to solid, the matter is getting colder. Solid to gas, sublimation. 00:09:44
solid to liquid melting liquid to gas boiling gas to solid deposition gas to 00:09:56
liquid condensation and liquid to solid freezing alright I hope you found this 00:10:09
helpful have a great rest of your day and goodbye for now 00:10:18
Autor/es:
IDOYA PÉREZ MARTÍN
Subido por:
Cp castilla alcobendas
Licencia:
Reconocimiento - No comercial - Compartir igual
Visualizaciones:
61
Fecha:
15 de abril de 2020 - 17:51
Visibilidad:
Público
Centro:
CP INF-PRI CASTILLA
Duración:
10′ 23″
Relación de aspecto:
1.61:1
Resolución:
1088x676 píxeles
Tamaño:
283.03 MBytes

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