Hi, everyone, it's Ms. Panchal here.

I'm really glad that you've decided to join me on today's science lesson.

So this is the second part of the lesson all to do with air resistance.

So you've already looked at understanding air resistance and planning an investigation, but today's lesson is going to be about doing the investigation but also reviewing it as well.

So let's get started.

So the outcome for today's lesson is I can carry out an investigation into air resistance and evaluate results.

So we're going to focus on some keywords in today's lesson and some of these keywords you would've come across before.

But we'll be using these keywords in our lesson today.

So we've got force, air resistance, fair test investigation, and conclusion.

So as I said, some of these words may be familiar to you already and some of you actually might know what they mean, but if you're not so sure, don't worry, because by the end of the lesson you'll know exactly what they mean.

So we've got some key words and their definitions here.

So what I would like you to do is pause the video here and I would like you to have a read over the definitions yourself and then click play when you're ready to continue.

Okay, so our lesson today is split up into two sections.

So the first part of the lesson is thinking about investigating air resistance, so doing the practical side.

And then the second part of the lesson is thinking about drawing conclusions from your results from the air resistance investigation.

So let's get started with the practical.

So when objects move, they have to push the air in front of them out of the way.

When the air hits the object, it creates a force.

So we can see a diagram here.

We've got air hits the bird and creates a force.

The bird flies in this direction.

So we can see that there are opposites.

This is called air resistance.

It is a type of friction force which acts between the air and the surface of the object.

Air resistance slows down moving objects.

So engineers and scientists are very interested in air resistance.

So we have Concorde here, which is a type of plane, a high speed aeroplane designed to minimise air resistance.

So we can see the shape of this aeroplane here is very slim line and which means that it is able to pass through the air a lot more easily and is designed to minimise air resistance.

So it's really important in the design of vehicles and structures that interact with the air.

So the people that design these vehicles, it's really important that they think about the shapes when they're designing.

Air resistance affects how easily objects move through the air.

So my question to you now is does air resistance affect objects moving on the ground, too? So we've just given an example of the Concorde aeroplane, but now I want you to have a think about does air resistance affect objects moving on the ground, too? So obviously the aeroplane is moving in the the sky, but does air resistance affect objects moving on the ground, too? Have a think.

Great job.

So fair test investigations can be used to learn about air resistance.

Jun is investigating air resistance and parachutes.

So his in inquiry question is, "Does the area of the parachute canopy affect air resistance?" So this is the inquiry question that Jun is hoping to answer and all the things that Jun does, it should be that it helps to answer his question.

He's going to make paper parachutes of three different sizes and compare how quickly they fall.

The variable he will change is the area of the parachute.

So in an investigation, the variable is the thing that you're going to be changing.

And for Jun here, in his investigation, he will change the area of the parachute.

So Jun has decided to drop each parachute from a height and time how long it takes to hit the ground.

So we've got an example diagram here.

So we've got the parachutes and we're going to time how long it takes to hit the ground.

And here we can see a stopwatch is being used as that's a reliable way of figuring out how long, in terms of time, it takes to hit the ground.

He will do this three times for each parachute size.

Why do you think it's important to do this? So why doesn't Jun just do each parachute size once? Why does he do it three times each? Have a think.

Excellent.

So the reason he's done that is when you repeat your test, you actually get a larger set of data, meaning the data you get is more reliable and it makes it more accurate.

So this helps him to make sure the results of the investigation are more accurate and actually you can draw better conclusions from these results because you've actually taken more results.

Whereas if you only take a few, it's quite difficult to actually draw conclusions from it.

So let's do a quick check of understanding based on the learning we've done so far.

So we've got two sentences here and we've got two gaps to fill.

When objects move, they have to (pause) the air in front of them out of the way.

Air resistance is a type of (pause) force.

So have a think to the learning we've done so far.

What are the missing words? Have a think and we'll go through the answer soon.

Great job.

So the answer is push and friction.

So when objects move, they have to push the air in front of them out of the way.

And the second sentence, air resistance is a type of friction force.

Great job, everyone.

So we're going to do a question just to check our understanding.

So the question is where does air resistance act? Is it A, between air and the insides of objects? Is it B, between surfaces of solid objects? Or C, between air and the surface of objects? Have a think.

Amazing job.

The answer is C, between air and the surface of objects.

Well done.

So we're going to move on to the first part of the task now.

So make parachutes to answer this inquiry question.

So let's recap on what the question actually is.

So the question is, "Does the area of the parachute canopy affect air resistance?" So there's quite a few different steps here.

So if you need to pause between the steps, then please do so.

So the first part is you're going to use a ruler and chalk to draw a 10 by 10 centimetre square on a recycled plastic bag.

You may need a partner, an adult, to help you hold the plastic bag down so that you can draw it accurately.

Once you've done that, you need to cut out the square.

Once you've cut out the square, you need to cut four lengths of string 30 centimetres long and tie them together at one end.

And there's a picture on the screen there to help you.

So remember the string needs to be exactly the same length.

So you should have four lengths of string, all of which are 30 centimetres long, and it's really important that they are the same length.

And make sure you tie them together at the end.

The next part is I want you to tape the loose ends of string to each corner of the square.

So we know that a square has four corners, and so I'll want you to tape the four different strings, ends of string to the different corners.

Once you've done that, we're going to attach a paperclip to the tied ends of the string and add a blob of sticky tack to weigh it down.

So you can see the picture of a step five there on the screen if you're not sure what that means.

And the last part of this practical preparation is make two more parachutes in exactly the same way, but instead of having a 10 by 10 centimetre square, you're going to have one that's a 30 by 30 centimetre and a 60 by 60 centimetre.

So you may be able to use a ruler for the 10 and 30 centimetre one, but for the 60 centimetre, you might need to use a metre stick or you can have a partner help you to put two 30 centimetres rulers together.

So what I suggest you do is pause a video here and make your parachutes.

Have a look at step three and step five on the board there in the pictures to help you just to make sure that you've done the correct steps and you have made the parachutes accurately.

Click play when you're ready to continue with the next part of the investigation.

So the next part of the investigation is to actually carry out the investigation.

So let's go over the inquiry question again.

Does the area of the parachute canopy affect air resistance? So to investigate air resistance, the first part of it is going to be dropping each parachute from the same height and time how long it takes to hit the ground.

The higher you drop, the more accurate your timing will be.

So it's important that you drop each parachute from the same height in order for it to be a fair investigation.

So there's an example here of how you can hold the parachute and how it can be ready to drop.

So I want you to make sure that it's the same height that you're dropping and that you time how long it takes to hit.

And I would definitely recommend using a stopwatch, as that's a really reliable way of measuring time.

Once you've done that, I want you to repeat this three times for each parachute.

Now, can you remember why we said it's really important to repeat this three times? Can you tell me? Great.

The reason we said that is because we have a larger data range, but also it helps us to get more reliable conclusions from our data.

Well done.

So the next part is actually recording your results in a table.

So let's remind ourselves of the inquiry question.

Does the area of the parachute canopy affect air resistance? So we've got an example table here, so you might want to copy this table out or you might want to print this out so it might be a little bit easier for you to write in.

So we've got the drop number one, two, and three, and then we've got the different parachute sizes as well.

And so what we're recording is the time taken for parachutes to fall in seconds, okay? So I want you to use this results table to help you.

So good luck with your investigation and I hope that everything goes well.

Remember to record your results and then check back into the lesson when you're ready to continue and we'll go through some example answers.

Off you go and have fun.

Great work, everyone.

I hope you had a really fun time completing that investigation.

I know I had a really great time creating all the parachutes and watching them drop.

So Jun has said, "Are your results similar or different to mine?" So this here is Jun's example results.

So these are the results that he got.

You may have gotten similar ones or you may have got slightly different ones, but please don't worry because they are most likely to be a little bit different, okay? Well done, everyone.

So that first part of the lesson is done.

So we've done the investigation side.

So we've done the practical side of the air resistance investigation.

So we're now going to think about drawing conclusions about air resistance from our data.

So we've done the investigation, we've recorded our results in our table.

So we're now going to analyse those results and that data and that will help us to draw some conclusions.

So let's get started with the second part of the lesson.

So the findings from an investigation can be summarised into a conclusion.

To do this, scientists need to make sense of their findings and answer the inquiry question.

So that's what I was saying before.

It's really important that everything you do in an investigation is targeted exactly to your inquiry question to help you actually answer it.

They also try to explain why this is happening.

So Jun reviews his investigation by checking to see if his data looks reliable.

What do you think? So let's have a look at Jun's results again.

Do you think his results are reliable? Have a look at his results.

Pause the video here, maybe talk with a talk partner.

Have a look really closely at the numbers there.

Are his results reliable? Have a think.

Great job, everyone.

So Jun looks at the data for the repeat drops for each parachute and notices a data point that he does not trust.

So you may have noticed this when you looked at Jun's data, but you may have also found this when you looked at your own data.

So can you have a think which data point you think Jun is a little bit unsure about? Well done.

It's the drop number two for the 30 by 30 centimetre parachute.

So we can see here that that is 0.

70 and that's quite different to the other two readings.

This time is much lower than the other measurements for this parachute.

He decides that this data might be unreliable and removes it.

So sometimes when you do investigations, there may be an anomaly.

So that's one reading that might be a little bit different and that's completely normal.

And sometimes these these things do happen.

So it's a good idea to maybe remove that data just so that it doesn't skew your conclusions.

So Jun looks for patterns in the data he has collected.

So let's recap on the inquiry question.

So does the area of the parachute canopy affect air resistance? So he writes a conclusion to answer his inquiry question.

What do you think Jun's conclusion should be? So I want you to pause the video here and have a really close look at Jun's results.

What conclusions do you think he would draw from this? Have a think.

Great job.

We're gonna go through now some of his conclusions.

So Jun concludes that my data shows that parachutes with larger areas took longer to fall to the ground.

You could use this observation to answer the original inquiry question.

So could you use this observation? How reliable, how in detail is this? So let's do a quick check of learning.

In which parts of an investigation write up would you expect to find a summary of the findings? Would it be A, in the method, B, in the evaluation, C, in the conclusion, or D, in the results? Have a little think.

Great job, it was actually in the conclusion.

Well done.

So let's have another question.

What conclusion would you draw from this data? So have a look at the data there on the right hand side.

So we've got the drop number, the material used, we've got paper and cotton, and the different drops.

Would you say that A, canopies made from paper create greater the air resistance, or B, canopies made from cotton create greater the air resistance? Have a think.

Great job.

The answer is B, canopies made from cotton create greater air resistance because we can see that it takes longer for that canopy and parachute to reach the ground.

Good job, everyone.

So we're going to move on to task B now.

So I would like you to use your own data to make your conclusion about your investigation.

So this is where you're going to use your data that you collected from your air resistance investigation.

And when you're thinking about your conclusion, there's a few questions and points I want you to think about.

So I want you to think about do you trust all of your data points? So have a go and have a look over your data again.

Are there any really odd readings? For example, in Jun's one, there was one and he removed it.

So maybe you need to do the same.

Or actually, in your data there might not be any anomalies.

I then want you to think about patterns.

What patterns do your results show? And what is your answer to the inquiry question and why? So your data might not show the same thing as Jun's and that's completely okay, but it may show something similar.

So I want you to have a go now at drawing conclusions from your data all about air resistance.

So if you need to have a look back at Jun's, the last couple of slides to help you guide your conclusion, have a go and we'll go through an example answer very shortly.

Off you go.

Great job, everyone.

Conclusions are often quite tricky to write, but you've all had a really fantastic go, so well done.

So your conclusion might be similar or different to this.

My numbers showed that the larger area parachute took the longest time to fall, so then more air must push against it, so the air resistance must be higher.

The middle size parachute was confusing because some of its data was similar to the smaller parachute and some to the big parachute.

A 10 by 10 parachute had a drop time much bigger than the others.

I must have dropped it from a greater height.

My data showed a clear pattern.

The lowest time was recorded for the smallest parachute and the longest time for the largest parachute.

So these are the conclusions that have been drawn as an example.

And maybe your conclusions have been a little bit similar, but also they may have been a little bit different.

But well done for having a great go at this investigation and having a go at writing a conclusion.

So we've come towards the end of today's lesson and you've doing lots of fantastic work today, so well done.

There's been a lot going on in today's lesson.

So we've learned that scientists often repeat tests to gather more information and make sure their results did not happen by chance.

So we said repeating the test helps us to gain reliable data and a larger set of data.

The findings from an investigation can be summarised in a conclusion, and within a conclusion, there's lots of different parts to it and this is where we can maybe think about explaining why something is happening.

And we need to ensure that the conclusion is actually answering our inquiry question.

So when we are planning and doing the investigation, it's really important that everything is helping us to answer that overall inquiry question.

And the last part here is the greater surface area on a moving object can increase air resistance.

So that's what our investigation showed us with the different size canopies of the different parachutes.

Now I want to say huge well done to you all 'cause there was a lot to cover in today's lesson.

You did lots of excellent practical work.

Then, actually, you looked really hard at the data and made really accurate conclusions as well.

Some of the work today was really tricky, but you all gave it a really good go and I'm so impressed.

So well done for all of your work today.

I hope that you had a great time and a fun time completing your investigation and I'm sure I will see you very soon in the next video.

So have a lovely rest of the day.

See you soon, bye-bye.