Hello scientists, my name is Mr. Wilshire and in this lesson we are going to be looking at everyday uses of thermal insulators.

The outcome for this lesson is I can identify and name thermal insulators in everyday life.

There are some key words to consider as we work our way through this lesson.

The first is thermal insulator.

Then it's material.

After that, thermal conductor.

Then it's suitable.

And finally, comparative test.

Don't worry if you're not too sure what some of these words mean.

The meanings have appeared on the screen for you now.

So if you need to, you can pause the video, recap the definitions, and restart when you're ready.

The first part of this lesson is called thermal insulators all around us.

Sam notices something strange at home.

Here's Sam.

I wonder what it is that she's found that's strange.

She says, "When I stand on the carpet in the living room, my feet feel warm.

But when I stand on the tiled floor in the kitchen, my feet feel cold." Hmm, here we are some feet on the carpet and some feet on stone tiles.

Hmm, they do look very, very different, don't they? Wonder what you think? Have you ever stood on a carpet or on stone tiles and felt this difference? Why is this? Why does this happen? Have a discussion with the person next to you and restart when you've done that.

So why does this happen? Hmm, I wonder why.

Let's move on.

Now, some materials are thermal insulators and some materials are thermal conductors.

Now the carpet insulates Sam's feet preventing the heat in them from being conducted away.

Here you can see some feet on a carpet.

Now the feet on the stone tiles, however, well, the stone tile conducts the heat away from Sam's feet.

This makes them feel cold.

I wonder if you've ever noticed this.

Did you notice that the heat was being drawn away from your feet? Did it feel like the stones were a lot colder? Now, a thermal insulator is a type of material that doesn't allow heat to pass through it very easily.

Thermal insulators are used for different purposes in everyday life.

Now, a thermal insulator is a material that does not allow heat to pass through it easily.

Thermal insulators are used for different purposes in everyday life.

I wonder if you can think of any.

Andeep says, well, "The only purpose a thermal insulator is to keep us warm in cold weather." Here you can see an image of a child wearing thermal insulators.

What thermal insulators can you spot? Hmm, well I can see she is wearing a hat.

It's got some bubbles on.

It looks like she's wearing a snood or a scarf to keep her neck warm.

Could also be just a very thick jumper.

And then on top of that, there is a waterproof coat as well.

Do you agree with Andeep here? Is the only purpose of a thermal insulator to keep us warm in cold weather? Discuss, restart when you've done that.

So what do you think? Is the only purpose of a thermal insulator to keep us warm in the cold weather? We definitely feel a lot warmer when we're wearing those things.

It can be freezing cold otherwise.

Hmm, well let's move on and find out more.

Plastic, wood and rubber are all suitable materials to be thermal insulators as well.

Here's some plastic in a mug.

There's some wood that's all been chipped up and some rubber used in tyres.

Can you think of any thermal insulators that you might find in your home? This may include some of the clothing that we looked at on the previous slide.

Have a think and a discussion.

Restart when you've done that.

So what did you think? Can you think of any thermal insulators in your home that aren't these types? Well, thermal insulators are used for keeping food and drinks warm.

Here you can see some plastic.

I wonder if you thought of this as well.

Plastic insulated mugs keep the drinks warm.

A wool tea cosy will keep teapots nice and warm as well.

And a polystyrene box will help to keep food warm.

It's also good for storage as well, isn't it? So all of these materials you can see here are examples of thermal insulators.

They're there to help keep food and drinks warm.

'Cause when you put the food or drink down on a colder surface, it's going to start losing the heat very quickly.

And if it's a type of item that you want to keep warm, you're going to want it to be in a good insulator.

Let's stop and think.

True or false, thermal insulators are not used in everyday life.

The correct answer here is false.

Can we justify our answer? Which of these two statements best fits? Is it that thermal insulators are only used for clothing to keep us warm in cold weather? Or is it that thermal insulators are used for different purposes in everyday life? The correct answer here is B.

Thermal insulators are used for different purposes in everyday life.

They're not just used for clothing.

In our homes, some insulating materials are used to protect us from heat.

Thermal insulators are used to stop us burning ourselves or surfaces when using hot objects in the kitchen.

Here you can see an example.

This is a cork place mat and it's been put down underneath a very hot item that's just come off of the stove.

You can also see here some fabric oven gloves.

Those oven gloves need to be fabric and they need to be quite thick in order to stop the user's hands being burned.

There's a wooden spoon here as well.

You can easily mix a hot mixture without your hand being burned because the heat isn't going to suddenly travel up the spoon and burn you straight away.

Plastic is a suitable material for the handles on some saucepans.

Not all of them though.

Here you can see a metal saucepan with a thick, rigid plastic handle.

Sam says, "Thick, rigid plastic is a thermal insulator.

It protects us from the heat of the saucepan." You wouldn't want to get your hands and go and put it straight onto the pan, would you, and lift it up? You would then burn your hands as they come into contact with the metal.

With the plastic handle that's been put onto it there you are able to pick it up safely and move it away.

So let's stop and think.

Where are thermal insulators used in the kitchen? Is it saucepan bases, saucepan handles, oven gloves or drinking glasses? The correct answer here is B and C.

Saucepan handles and oven gloves.

You wouldn't want an insulator on the bottom of a saucepan because then it wouldn't heat up and you also wouldn't want to thermally insulate some drinking glasses.

Now air is a good thermal insulator as well.

Natural materials like cork, wood, straw, coconut, and wool, which contain pockets of air are good thermal insulators.

There you can see some examples of a cork, some straw and coconut fibre.

So why are they so good at being thermal insulators? Have you ever seen these being used as thermal insulators? Well, I know that I can put a cork inside a bottle that's going to stop the air getting into the bottle.

I can use the straw to put on the roof of a house that's going to stop all the heat from escaping, isn't it? And the coconut fibre there as well.

Well, that might be very good to use maybe some gloves to be able to pick something up.

You can even wrap it around yourself to keep yourself nice and warm.

Although it might be a little bit scratchy.

Scientists and engineers have developed materials which deliberately include pockets of air to make them good thermal insulators.

I wonder if you can think of any.

Hmm, some of these examples are polystyrene and foam.

Here you can see some polystyrene and there you can see some foam.

These products are designed to keep things safe and also to keep things nice and cool on the inside.

The air bubbles that are trapped inside these materials here make them very good thermal insulators.

Some products are designed to deliberately include pockets of air to make them suitable for thermal insulation.

For example, lots of clothing that is designed to keep us warm, such as winter jackets and sports clothing contain trapped air to stop us losing heat from our bodies.

Thermal insulators are used to keep our homes warm too.

Some windows are double glazed.

This means that they've got two layers of glass, then they have a pocket of air trapped in between them.

The trapped air reduces the transfer of heat through the window.

So that means when it's cold outside it can be hot inside and the hot air isn't going to escape the house through that air pocket.

So that means when it's cold outside and nice and warm and toasty inside, that means the hot air isn't suddenly going to escape through the window due to that air barrier.

Hot water pipes and tanks are often covered with insulated materials too.

These contained pockets of air to help stop hot water from losing heat.

There you can see some insulation for pipes.

Have a look out in your school or at your home.

Have you seen anywhere that pipes like this are insulated? Let's stop and think.

A padded jacket is a good thermal insulator.

Is that true or false? The correct answer here is true.

Can we justify our answer? Is it because the material of the jacket contains trapped pockets of air? Or is it because the material of the jacket is waterproof? The correct answer here is A.

The material of the jacket contains trapped pockets of air.

Here is task A.

Look at the household objects in the images below, which of the items are designed to be thermal insulators? Is it the soap dish or the wooden spoon? There's a woolly hat and takeaway cup and a whisk as well.

There's a metal spoon, an oven, glove, a tea cosy, a drinking glass, and a bowl of fruit.

So which of those items are designed to be thermal insulators? Have a think and record some of your answers.

Restart when you've done that.

So how did you get on? Here's some possible answers that you could have had.

Items designed to be thermal insulators are the wooden spoon, the oven glove, the tea cosy, the takeaway cup, and the woolly hat.

All of those items are really good thermal insulators.

As an extra challenge, here you can have a go at thinking of some other items that could be thermal insulators.

Maybe see if you can write down three or four more items that you can include in this list.

The next part of this lesson is called keeping cold things cold.

Sometimes we want to keep things cold rather than warm.

Thermal insulators can be used here as well.

They can also be used to keep things cold.

What types of things might you want to keep cold? Have a quick think of some examples and restart the video when you've done that.

I wonder what you thought of? Are there any other items that we think might want to stay cold instead of warm? Andeep says, "Ice cream." That's a good example.

Sam says, "Frozen pizzas." Sophia says, "Milk." How do we keep things cold then? Have a think about how we're going to keep all these items cold.

Not just using the fridge or the freezer.

How else? Have a think, restart when you've done that.

So how do we keep things cold? Well, let's find out more.

We use fridges and freezers to keep food and drinks cold when we store them.

But what is it about fridges and freezers that make them particularly suitable for keeping things cold? The walls and doors of fridges and freezers are made with a suitable thermal material that insulates it.

We also use cool boxes and cool bags to keep food and drinks cold when we transport them.

I wonder if you thought of these two items when you were having your discussion before.

Cool bags often have two layers.

They're made of different insulating materials with air trapped in between.

So stop and think.

Thermal insulators are only used to keep warm things warm.

Is that true or false? The correct answer here is false.

Can we justify that? Is it because thermal insulators are only used to keep cold things cold? Or is it because thermal insulators can be used to keep cold things cold or warm things warm? The correct answer here is B.

Thermal insulators can be used to keep cold things cold or warm things warm.

Andeep has a question.

It's about keeping cold things cold.

Andeep says, "Which cup is most suitable for keeping cold water cold?" His friends have already investigated which cups keep warm water warm.

So how could Andeep use a comparative test to investigate which cup is most suitable for keeping cold water cold? What do you think? Have a discussion and restart when you've done that.

What did you think of? Is there a suitable way to do this? Let's find out more.

In a comparative test, the variable that's being changed has names or labels such as the names of plants.

Andeep says, "In a comparative test, only one variable is changed and one is measured.

All other variables must be controlled." When we control variables, it means we keep them the same throughout an investigation.

Which variables will Andeep need to control in his test? So in his test, he's more than likely going to have chosen something that's going to keep something cold.

That could be a cup, for example.

Or maybe there's another material that you thought about.

So which variables is Andeep going to need to control here? Is he going to change the type of material or is it going to do something different? Have a discussion, restart when you've done that.

How did you get on? What did you think of? Let's find out more.

There are some variables that Andeep cannot control easily.

I wonder if you can think of any here.

Andeep says, well, "When using different cups I'll try to use cups that are similar sizes, thicknesses and shapes, but unless I get them specially made for this investigation, the cups will not exactly be the same." Yeah, that's kind of out of Andeep's control, isn't it? The variables that Andeep will control, which things that'll keep the same, are the amount of cold water, the start temperature of the water, the temperature of the room, and the time he carries out the experiment for.

The variable that he's going to change is the type of cup ergo, the type of material that he's testing.

The variable that he's going to measure is the temperature change of the water in each cup over time.

Andeep says, "I wonder if the cup that was most suitable for keeping warm water warm will also be the most suitable for keeping cold water cold?" Hmm, good point.

What do you think? Do you agree with Andeep here? Is it going to be the most suitable? Well, let's find out more.

Stop and think.

Which statement about comparative tests is correct? Is it that they can be used to identify which material a cup is made from? Is it that they can be used to investigate which cup is most suitable for keeping drinks cold? Or is it they can be used to research which cup is most suitable for keeping drinks cold? The correct answer here is B.

They can be used to investigate which cup is most suitable for keeping drinks cold.

Here is task B.

Step one is to use the method on the next slide.

Or you can use your own ideas.

You then need to carry out a comparative test investigation to answer Andeep's question, which cup is most suitable for keeping cold water cold? Part two of this is to collect some data to answer this inquiry question.

So have a look on the next slide here for the method.

Now one is pour 100 millilitres of cold water into three different types of cup.

Two, as soon as the water is in each cup, measure the temperature of the water using the thermometer.

Record this as the temperature at zero minutes.

Three, time 10 minutes using a timer, then measure and record the temperature of water in each cup again.

Four, calculate the difference in temperature for the water in each cup.

Now you could record your own results in a table like the one on the next slide.

Here is a slide that you could use.

Now, the time in minutes is down the side.

You might use cups made of different materials to these though, so you are going to need to decide what needs changing.

Best of luck with your task.

Restart the video when you've done that.

How did you get on? Now your results could be similar to these.

You can see here that the time in minutes was set at zero and the ceramic cup, the plastic cup and the metal cup all had a temperature of five degrees.

After 10 minutes, the ceramic cup was 12 degrees, the plastic cup was six and the metal cup was 11.

And then looking there at the difference between the two temperatures, well, which of these is going to tell us which cup is best to be used to keep things cold? You can use that table to give you some results and then you can write them up in a description very similar to this.

You had to answer the inquiry question, which cup is most suitable for keeping cold water cold? The plastic cup kept the water to the coldest because it had the smallest change in water temperature from six degrees to five degrees.

That's a change of one degrees, isn't it? The ceramic and metal cups were not as suitable for keeping the cold water cold, 'cause the water temperature increased more in these cups than in the plastic cup.

Our results show that from the cups we tested, the plastic cup was most suitable for keeping cold water cold.

Maybe you found something very similar to this as well, or maybe you found something different depending on the types of materials that you used.

Well done for completing this investigation.

Let's summarise our learning.

Thermal insulators are used for different purposes in everyday life.

Thermal insulators are used to stop us burning ourselves or surfaces when using hot objects in the kitchen.

Materials that contain trapped pockets of air make good thermal insulators.

Thermal insulators can be used to keep cold things cold.

A comparative test can be used to investigate which cup is most suitable for keeping cold drinks cold.

Well done for investigating.

Hopefully you've got a better idea now about how you might be able to keep warm in the winter or cool in the summer.

You've got to think about thermal insulators.

I've been Mr. Wilshire, thank you very much for listening.