Hello everyone.

My name is Mrs. Mehrin and I am so excited to be learning with you today.

I'm going to have a great time learning all about different surfaces and we are going to do brilliantly.

So welcome to today's lesson from the unit, simple forces including magnets.

And this lesson is called Different Surfaces Do and Review.

And by the end of today's lesson, we're going to be able to do an investigation and review it.

So we are going to be focusing on exploring how to do an investigation around different services and what steps we need to do to complete it and how we can represent our answers.

So some of our learning is brand new, but I am here to help you and we are going to be building on some of your previous learning of planning a fair test.

Now sometimes, learning can be a little bit challenging, but the great thing is, it means that we can really work hard together and learn lots of new fabulous things.

So your lesson outcome for today is to carry out tests and compare how things move on different surfaces.

So let's take a look at some of our keywords today.

So we have got surface, friction forces, rough, smooth, conclusion.

Now you may have come across a couple of these words before, so let's take a look at what they mean.

So the surface is the top or outside layer of something.

Friction forces are forces which act between the surfaces of objects.

Rough surfaces are uneven or bumpy, smooth surfaces are even and not bumpy.

In a conclusion, scientists explain what the results show or mean.

So our lesson is going to be broken up into three sections today.

So let's begin with our first section comparing different surfaces.

Okay, so I'd like you to explain to a partner what a surface is.

Now have a little think.

Can you remember from our key words what it might mean? If you don't have a partner, you can always tell your teddy or a toy.

I'll give you some time to have a little think or explain now.

Fantastic, so a surface is the top or the outside layer of something, well done.

So objects move differently over different surfaces.

For example, a smooth tarmac road or a rough stone path.

Some surfaces are easy to move over but others are difficult.

So let's have a look at two of these pictures.

We've got one, we've got a car driving on ice and a car driving on sand.

Now do you think cars move the same way on ice and sand? And why do you think that might be? Have a little think.

You might like to pause the video here.

Fantastic, well done.

So you might have said that actually they won't be moving in the same way on ice and sand because ice is a smooth surface and sand can be a bit bumpy and uneven.

So they would move in different ways.

So we've got Izzy over here and we are helping Izzy to compare how a marble moves over different surfaces.

Our question is, does the surface a marble rolls on affect how far the marble moves? Now a fair investigation can be carried out to compare how different surfaces can affect how things move.

Now let's do a quick quiz to check our understanding.

So which statement below is true? Is it A, objects move differently over rough and smooth surfaces, B, objects move in the same way over rough and smooth surfaces, or is it C, all objects move in the same way if you give them the same push, have a little think.

Fantastic, it's A, objects move differently over rough and smooth surfaces.

Well done, you are doing brilliantly.

So let's see if you can find the missing word to go into this sentence.

Scientists can carry out to compare two or more things.

Have a little think, what word could be our missing word for the sentence? Fantastic, well done.

Its scientists can carry out fair test investigations to compare two or more things.

So this inquiry question is for a fair test investigation, does the surface of the playground affect how far a ball rolls? So which of these things are being compared? Is it A, different surfaces or B, different walls? Fantastic, well done.

It's a different surfaces.

So let's have a look at task A, comparing different surfaces.

So your first task is to set up your test and it might look like this.

So you may have a book to support the ramp, which is on the floor and you've got a marble and half a kitchen roll tube that's stuck to the ramp.

Now you may decide that you want to make your ramp using a plank of wood and then you have your surface which you'd like to test and rulers or take measures to see how far the marble rolls.

So test each surface, hold the marble at the top of the ramp and release it without pushing it.

Measure and record how far marble rolls.

And then you're going to change the surface and repeat.

So you may like to record your results in a table like this one.

So you have two sections, one for surface and one for the distance the marble rolled in centimetres.

So if you'd like, you can pause the video here and copy this table down or you may decide you'd like to record your results in a different way.

So pause the video here if you need to.

Fantastic, well done.

So let's have a look at what Izzy says.

So Izzy says, here are my results.

Are yours the same or different to mine? Well, Izzy has chosen three surfaces, carpet, floor, tiles, tray of sand.

She found that on the carpet, the marble rolled 40 centimetres.

On the floor tiles, it rolled 304 centimetres and in the tray of sand, it rolled one centimetre.

Now I wonder why the marble rolled a different distance on each of those surfaces.

Let's find out.

So our second part of today's learning, it's friction forces slow down moving objects.

So when an object moves across a surface, a friction force is created.

This acts against the movement and slows down the object.

As you can see in this picture, the tyres move in this direction on the road surface and friction forces act in this direction to slow the car down.

Without friction forces, moving objects would never slow down or stop moving.

What will friction forces cause to happen here do you think? Have a look at this picture.

Fantastic, hockey balls hit along the ground slow down and stop because of friction forces.

What will friction forces cause to happen in this picture here? Have a think.

Fantastic, well done.

Inline skates slow down and stop because of friction forces.

So when this ball rolls, the surface of the ball moves across the surface of the playground.

This creates friction forces between the two surfaces.

Let's have a look at this diagram in closer detail here.

So you've got the surface of a ball and the surface of the playground, and in between those you have friction forces.

Some surfaces create greater friction forces than others.

Some surfaces are rough, like rough sandpaper, some surfaces are smooth, like smooth stone steps.

Which type of surface do you think creates greater friction forces? Fantastic, well done.

Rough surfaces create greater friction forces against a moving object than smooth surfaces and a rough surface slows the object down more when it's moving.

So let's check your understanding, true or false? Friction forces slow down moving objects.

Is that true or is that false? Fantastic, it's true.

Let's see if you can put that into a sentence.

I think this because A, when I kick a ball along the ground, it eventually slows down and stops moving.

Or B, when I kick a ball along the ground, it keeps moving at the same speed forever.

Fantastic, the answer is, A, I think this because when I kick a ball along the ground, it eventually slows down and stops moving.

Well done, you are doing so well.

Now let's see if you can work out what missing words should be in this sentence.

Rough surfaces slow down moving objects, than smooth surfaces.

What word do you think belongs in this sentence? Have a think.

Fantastic, well done.

The answer is more, rough surfaces slow down moving objects more than smooth surfaces.

Okay, let's look at task B.

Friction forces slow down moving objects.

So Aisha and Alex are discussing how a toy car rolls on a rough surface compared to on a smooth surface.

Aisha says, on the rough surface, the toy car will roll faster than on the smooth surface.

And Alex says, on the smooth surface ,the toy car will roll faster than on the rough surface.

Who do you agree with and why? Have a think.

Fantastic, let's see who was correct.

Alex is correct.

On the smooth surface, the toy car will roll faster than on the rough surface.

The smoother the surface, the faster an object will travel.

This is because a smooth surface will create less friction forces to slow moving objects down.

Well done.

Sofia and Jun are discussing how a toy car rolls on a rough surface compared to on a smooth surface.

Sofia says, on the rough surface the toy car will roll further than on the smooth surface and Jun says, on the smooth surface the toy car will roll further than on the rough surface.

Who do you agree with and why? Fantastic, let's see who was correct.

It was Jun, Jun is correct.

On the smooth surface, the toy car will roll further than on the rough surface.

The smoother the surface, the further an object will travel.

This is because a smooth surface will create less friction forces to slow objects down and stop them from moving.

Now we're onto the final part of our lesson.

Scientists use their results to make conclusions.

During a fair test investigation, scientists record their results.

Some results are observations, things the scientist has seen.

So if you look at that picture, you can see a scientist recording their observations.

Some results are lists of data, things the scientist has measured and you can see in the picture the data in graphs.

To complete the investigation, scientists need to decide what their results tell them.

They need to make sense of their findings and answer the inquiry question.

This is called making a conclusion.

Jun did an investigation to answer the question, do different surfaces affect how far I can slide my pencil case? Here is Jun's table of results.

So we can see he's used three surfaces, wood, carpet and tiles.

On the wood, his pencil case travelled 63 centimetres.

On the carpet, it travelled 37 centimetres and on the tiles it travelled 90 centimetres.

What do you think Jun's results show? Fantastic.

So you may have said that the tiles must have been a really smooth surface because the pencil case slid for 90 centimetres and you may have said the carpet was a rough surface because the pencil case only slid 37 centimetres.

Jun notices that on the smoother surfaces, his pencil case slid further.

Jun's conclusion is my investigation shows that the smoother the surface, the further my pencil case could slide.

I think this is because smoother surfaces create less friction forces to slow things down.

Lucy did an investigation to answer the question, which material makes the bounciest ball? Here are Lucy's results.

She used three different materials to make her ball, metal, rubber and plastic.

Now her metal ball bounced two centimetres, her rubber ball bounced 10 centimetres and her plastic ball bounced five centimetres.

What conclusion would you make from those results? Would it be A, the metal ball was the bounciest, B, the rubber ball was the bounciest or C, the plastic ball was the bounciest.

Fantastic, well done.

It would be B, the rubber ball was the bounciest.

Now which two of these items would you find in the conclusion? Would it be A, a drawing of observations? B, an explanation of what the results mean.

C, a list of measurements or D, an answer to the inquiry question.

Fantastic, well done.

Let's see what answers we have.

It would be an explanation of what the results mean and an answer to the inquiry question, well done.

So let's have a look at task C.

It says, does the surface a marble rolls on affect how far the marble moves? And that was our inquiry question from task A.

So what I'd like you to do is to look at your data from task A and talk about what your data shows about the distances the marble travelled on different surfaces.

Now Izzy has some sentence artists to help us.

She said, our results show that the marble travelled the distance on and our results show that the marble travelled furthest on.

Now if you don't have a partner to talk to, remember, you can talk to your teddy or a toy or you can simply write down your answers.

If you'd like, you can pause the video here so you can do that.

Fantastic, well done.

So you may have said something like Izzy and you may have tested different surfaces.

Now, Izzy said, our results show that the marble travel the least distance in the sand tray.

And she also said, our results show that the marble travelled furthest on the tiles.

I'd like you now to write a conclusion for the inquiry question.

Does the surface a marble rolls on affect how far the marble moves? I'd like you write a conclusion by saying what your results show and then explaining what that tells you about the friction forces on the different surfaces.

You may like to use these sentence starters.

Our results show that the marble travelled.

I think this is because, our results show that the marble travelled.

This shows that.

You can pause the video here if you'd like, and I'd like you to write down your conclusion.

Fantastic, well done.

So you may have got something similar to this conclusion.

Our results show that the marble travelled the shortest distance on the carpet.

I think this is because the friction forces slowed the marble down as it was moving along the surface of the carpet.

The carpet was the roughest surface, so it created the greatest friction force.

Now it may look like that or you may have had different ideas and that's okay too.

So Izzy is asking whether or not your conclusion is similar or different to hers.

And she said, I wrote my conclusion.

Is it similar or different to yours? Izzy said, my results show that the marble travel the greatest distance on the tiled floor.

I think this was because there was not much friction force to slow the marble down.

The tiled floor was the smoothest surface, so it created the least friction force.

So our summary for today, objects move differently over different surfaces.

Scientists can carry out fair test investigations to compare different surfaces.

Friction forces slow down moving objects.

A rough surface will create a greater friction force against a moving object than a smooth surface.

In a conclusion, scientists can explain what the results show or mean.

Thank you all so much for your hard work and critical thinking today.

I have really enjoyed doing our lesson on different surfaces and doing an experiment and writing up a conclusion.