Hi, everyone.

It's Ms. Pancho here.

I hope that you are well.

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

So our lesson today is going to be learning all about levers and how they can help us.

We're going to be looking at lots of different examples that you'll see in your everyday life.

So we've got lots of learning to do today.

So let's get started.

So the outcome for our lesson today is I can describe how levers can make difficult work easier.

So here are some key words that we're going to use in today's lesson.

Now, some of you may have been familiar with these words before and some of you may not be so sure, but don't worry because we're going to go through all of the meanings and definitions throughout today's lesson.

So I'm just gonna read them out to you.

We've got lever, force, load, effort, and pivot.

So I'm going to just put up some definitions now.

And so I would like you to pause the video here and just have a read over these definitions on your own quietly, and then click play when you're ready to continue.

Great.

I hope that's given you a bit of an overview of what the words mean and we're going to be using these words in today's lesson.

So our lesson today is going to be split up into two parts.

So we're going to first look at levers and how they help us, and then we are going to think about investigating levers.

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

So my question to you is, have you ever tried to lift another person up? It's pretty difficult, right? My next question is have you ever been on a seesaw? So if you've been to your local park, you may have been on a seesaw before.

So on a seesaw, you lift a person up, but it doesn't seem very hard.

So when you're physically lifting someone up in a seesaw, technically, you are still lifting up a person, but actually you're doing it in two different ways.

Why do you think that lifting someone up on a seesaw is easier than lifting someone up with your hands? Have a think.

Great.

So that's what today's lesson is all about, is thinking about how we can use levers to actually help us make difficult work easier.

So a seesaw is an example of a lever, and we've got an example of a seesaw there on the slide.

It allows us to apply a smaller force to an object and have a greater effect than when an item is lifted without a lever.

So the lever is actually there to help us.

For example, a seesaw allows you to lift a person with less force than if you had to pick them up in your arms. So a lever is a simple mechanism or machine which is useful for lifting or moving things.

It has three main parts.

So the first part is the load, and this is the object or weight you lift.

So if we look at the seesaw example, the load here is the person that's at the bottom that needs the lifting.

And then we've got the effort.

This is the force needed to do a job.

Here, it is the effort to lift the load.

So in this example, the effort is how much force is needed to lift the loads or lift the other person.

And then lastly, we've got the pivot, and this is the fixed point around which the lever pivots or turns.

So these three main parts are really important to a lever, and we're going to look at these in more detail throughout the rest of the lesson.

So let's do a quick check of our understanding so far.

So true or false, a lever is a simple mechanism which is useful for lifting things.

The object you lift with a lever is called the pivot.

Do we think that's true or false? What do you think? Great.

The answer is false.

Now I'm going to give you two options and I want you to think about why it is false.

Do we think A, the object you lift with a lever is called the load, or do we think B, the force you apply to the load to make an object move is called the effort? Which one do you think is correct? Have a think.

Super work, everyone.

The answer is A, the object you lift with a lever is called the load.

So again, we're focusing on those three key elements of a lever and those keywords, and we'll be constantly going back to them in today's lesson.

Good job, everyone.

So let's move on.

So with some levers, the force or effort is applied as a push.

So the effort applied as a push above the lever.

So we can see another example of a lever here.

So we've got the load, which is what's weighed down, which needs lifting, we've got the pivot, and we've got the effort.

With other levers, the force or effort is applied as a pull.

So here we've got another example where the load is on the left-hand side, we've got a pivot and the effort applied as a pull below the lever.

So some effort is a push and some effort is a pull.

So let's have a quick check of our learning so far.

Which image of a lever is correctly labelled? Now think really carefully about this and look really carefully at the labels.

So we've got diagram A, B, and C.

So pause the video here and have a really close look and think which lever is labelled correctly.

Have a go.

Excellent work, everyone.

Well done.

The answer is C.

So in diagram, C here we've got the load, which is at the bottom of the seesaw, we've got the effort, which is at the top, and we've got the pivot.

Well done, everyone.

So engineers are interested in how scientific ideas can help solve problems and make our lives easier.

So engineers are always working really hard to help us in our everyday lives and thinking about what they can make or create or design in order to help us with our everyday lives.

In the past, engineers designed the levers we use in our day-to-day lives like ring pulls on cans, nail clippers, and bottle openers.

So these are things that we use in our everyday life.

For example, a tin of soup you might have on a cold winter's day.

It has that ring pull on the top to help you open the can.

Nail clippers that you use to cut your nails.

That is also an example of a lever.

And also a bottle opener.

Levers are all around us.

They make difficult jobs like moving and lifting easier.

So we mentioned this at the beginning of the lesson.

So levers are there to help us.

A wheelbarrow is a lever with the pivot at the end.

It allows us to lift and move heavy objects with a smaller effort, force.

So a wheelbarrow is also a type of lever, but it just looks a little bit different.

So we can see here the pivot is at the end, we've got the load, and we've got the effort.

And in this example, the effort is pulling up.

Well done, everyone.

Let's do a quick check of our learning.

Sam is trying to lift a heavy boulder.

How would using a lever affect the force needed to lift it? Is the answer A, a greater force would be needed, B, a smaller force would be needed, or C, the same force would be needed? So think carefully about the learning that we've done in our lesson so far and think about what the correct answer would be.

Have a think and we'll go through the answer soon.

Super job, the answer is B.

So using a lever here would actually mean that a smaller force would be needed, and therefore, it would be easier to lift the heavy boulder.

Super work, everyone.

Well done.

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

So you are going to explore the parts of a lever and you're going to need some equipment.

So you will need a rubber, a pencil, and a ruler.

So make sure you have those three pieces of equipment with you.

The first thing you're going to do is use the equipment provided to create a model of a lever that would be used to help lift a heavy load.

So using your rubber pencil and a ruler to create a lever.

Then once you've created it, I would like you to draw your lever and label the pivot and the load.

If you need to, go back to the beginning part of the lesson to help you remember where the pivot is and where the load is.

How would the lever make it easier to lift the load? Have a go at this task and click play when you're ready to continue.

Super job, everyone.

Well done.

I hope you had a great time creating those levers with the rubber pencil and a ruler.

So you might have done something like this.

So you've used the pencil as the pivot and the rubber as the load.

Did you do something like this? So using the lever would mean that less force is needed to lift the load than without it.

Well done, everyone.

Fantastic work.

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

So first, you've now made the lever, which is fantastic, but now you are going to explore how the levers actually work.

So the first part is actually exploring moving the pivot to lift the load.

So in this example, we said the pivot is the pencil.

And I want you to have a think about does moving the pivot make a difference to the effort needed to lift the load? So what I want you to do is explore moving the pivot in different places and think about does it make a difference to the effort needed to lift the load? And in this case, the load is the rubber.

Have a go.

Super work, everyone.

Well done.

So you may have noticed something like this.

Moving the position of the pivot does affect how much effort is needed to lift the load.

So I hope that when you did your exploration of moving the pivot, you did actually notice it does affect how much effort is needed.

Amazing work.

So well done, everyone, for completing that first part of the lesson.

So we now have a really good understanding as to what levers are, but also how they can help us as well.

So we're now going to move on to the second part of the lesson where we're going to investigate levers.

So levers don't always have the pivot in the middle, like a seesaw, and that was just what you looked at explored.

The pivot can be anywhere along the length of a lever.

So if we have a look at these three diagrams here, what do you notice about the pivot? Great.

You can notice here the pivot's actually in three different places.

So in the first example, the pivot is very close to the load.

In the second diagram, we can see the pivot is in the middle between the load and the effort.

And we can see in the third diagram here, the pivot is a lot closer to the effort.

Levers require different amounts of force depending on where you put the pivot.

With this lever, the pivot is very close to the load and little effort is needed to move the load.

So you have a look at this diagram carefully.

The pivot is very, very close to the load, therefore, it will take very little effort to push down to actually lift the load.

If we look at a different diagram now, with this lever, the pivot is very far from the load.

So we can see the pivot is very far away from the load and this would mean that a lot more effort would be needed to move the load.

A lot more push down on the effort side in order to lift the load.

So let's move on.

So scientists can carry out investigations to investigate levers and their effects.

In this way, they can find out how much a lever is helping to reduce our effort or the force we need to use.

And that's our diagram there of the load, pivot, and effort.

So let's do a quick check of our learning.

Levers require different amounts of, or effort depending on where you put the.

What do you think are the missing words? Have a think.

Super work.

The first missing word is force and the second missing word is pivot.

So levers require different amounts of force or effort depending on where you put the pivot.

In the diagrams, we just looked at show that really clearly.

Super work, everyone.

Well done.

You're doing great so far.

So let's do another quick check of our learning.

Which of these levers would require the most effort to lift the load? So pause the video here and look really carefully at all three diagrams. I'm gonna repeat the question, so listen really carefully.

Which of these levers would require the most effort to lift the load? So think back to the learning that we've just done and think about which diagram is correct.

Have a think and we'll go through the answer soon.

Super work.

The answer is C.

So we can see that the pivot here is very far away from the load, therefore, the most amount of effort would be needed out of all these three diagrams in order to lift the load.

Great job, everyone.

Well done.

So we're going to move on the next task now.

So I would like you to use the equipment to make a lever.

So there are a few different steps that we need to follow here.

So if you need to pause the video after each step to ensure that you've done it correctly.

And there's a diagram here on the slide to help you if you are unsure how to set up the equipment.

So first, you need to attach an elastic band to the end of a wooden ruler or rod.

And then position the ruler so that the end with the elastic band is hanging over the edge of the table.

Then slide a pen under the ruler to act as a pivot.

And then tape a load on the other end of the ruler.

Now you can choose what your load is going to be.

So pause the video here and just double check that your equipment is set up correctly.

Well done, everyone.

Then you need to make sure you've hooked a force metre into the elastic band.

So again, make sure you have a look at this diagram.

Make sure your equipment looks very, very similar to ensure that the investigation is successful.

Good job, everyone.

So what I would like you to do is change the position of the pivot and measure the force, which is the effort, needed to lift the load.

So we've got a diagram here to help you understand this.

So we're changing the distance from pivot to load.

So the first part is starting with the pivot at 20 centimetres from the load, gently pull down on the force metre until the load is lifted.

Record the force needed to lift the load.

So we first starting at 20 centimetres, which means the pivot is quite far away from the load.

Then I want you to move the load five centimetres closer to the pivot.

And again, record the force needed to lift the load.

And think about have you noticed anything? And then lastly, I want you to repeat step B twice more until the load is only five centimetres away from the pivot.

So in this investigation here, we're changing the distance from the load to the pivot and thinking about the impact that has on how much force is needed to lift the load.

Here is a results table that you can use to help you record your results.

So we're changing the position of the pivot and we're going to measure the force needed to lift the load.

So here is an example table that you can use to help you record your results.

You might want to pause the video here and copy out this table, or you can print out the slide, whichever you find is easier.

So in the table here, we've got the force needed to lift the load, and that's in newtons, and we've got distance from pivot to load.

So we've got 20 centimetres, 15 centimetres, 10 centimetres, and five centimetres.

So write your results into this table.

And once you've done that, I would like you to have a think about what your results show.

How does moving the pivot closer to the load affect the force needed to lift the load? So do you spot a pattern with your data? So pause the video here.

And if you need to, go back through over the last couple of slides just to make sure your equipment is set up correctly and you know exactly what you're going to do.

I hope you have a great time investigating these levers and click back onto the video when you're ready to continue and we'll go through some example answers.

Off you go.

Super work, everyone.

Well done.

So you may have got results similar to this.

So in this person's example, they had 18 newtons for the 20 centimetres, 12.

5 newtons for the 15 centimetres, four newtons for the 10 centimetres, and 1.

5 newtons for the five centimetres.

Were your results similar or a little bit different? So this person has concluded here that when the pivot was closest to the load, less effort or force was needed to lift the load.

Did your results show the same thing? Or did they show something a little bit different? Well done for having a go at this investigation.

It was quite tricky to set up all the equipment, but you had such a fantastic go and I'm so impressed with your work.

Well done.

So we've now come towards the end of our lesson all about learning about how levers can help us.

So we've learned that a lever is a simple mechanism or machine which is useful for lifting or moving things.

We've learned that a lever allows a small force to have a greater effect.

And the object you are moving is called the load.

The force you apply to the load to make an object move is called the effort.

And a lever requires different amounts of force depending on where the pivot is positioned.

So we've come to the end of the lesson now and I'm so impressed with all of your learning today.

You've all done such a fantastic job with the investigation, but also with all those keywords to do with levers.

Amazing work, everyone.

Fantastic job.

I hope you have a great rest of the day and I'm sure I'll see you very soon in the next science video.

Bye-bye.