【臺(tái)詞】Do You Know S1-05 Bike Chain and Tennis Ball

【臺(tái)詞】Do You Know S1-05 Bike Chain and Tennis Ball

2級(jí)Do You Know S1-05a Bike Chain1人有 · 評(píng)價(jià)1 · 書評(píng)1 Do You Know S1-05a Bike Chain ????250626 看2小段s1-5。

2級(jí)Do You Know S1-05b Tennis Ball1人有 · 評(píng)價(jià)1 · 書評(píng)1 Do You Know S1-05b Tennis Ball 橡膠rubber ????250626 看2小段s1-5。

Hello, I'm Maddie, and today I've

come to the park to ride my bike.

Have you learned how to ride

a bike?

Now, they say once you've learned,

you never forget,

but do you know how a bike works?

Let's find out.

When I ride my bike, I put my hands

on the handlebars, like this,

and I put my feet on the pedals.

And you can see that as I push the

pedals, the wheels go round too,

and this is what makes

the bike move.

But how do the pedals make the

wheels go round?

Well, that's thanks to something

called the chain.

The chain is this large

metal loop here.

It's made of lots of smaller pieces

of metal that are fixed together,

called links.

The chain goes round this large

metal cog, which is attached

to the pedals, and you can follow it

back to the smaller metal cog,

which is attached to the wheel.

But to see how the chain makes the

bike move, we need to take

a closer look.

RING RING

When you push the pedals with your

feet, they turn the big cog in

the middle of the bike

round and round.

The big cog has teeth all around the

edge and the chain links have

little holes in.

The holes hook on to the teeth.

When the pedals turn the big cog,

the teeth pull the chain around too.

At the other end of the chain is

a smaller cog.

This one is attached to the

back wheel.

As the chain is pulled around the

big cog by the pedals,

the holes hook

on to the teeth on the little cog

which turns the back wheel and

pushes the bike along.

This means we can go zooming

along on our bikes.

Wheee!

RING RING

How clever is that?

I don't know about you, but I want

to see all of that

going on for real.

So, I'm going to go on another

ride on my bike,

but so you can see the chain working

close up in action,

I've got my special little

camera here.

Let's attach it to the bike.

Let's go.

Can you see my feet on the pedals

turning the big cog?

And, look, can you see the chain

moving and the little cog

that's turning the back wheel?

Can you hear the sound of all the

parts working together?

GEARS CLICK

It's like clickety-click,

clickety-click, clickety-click.

Brilliant.

I love riding my bike.

But what about the front wheel?

The front wheel isn't attached to

a chain so how does it move?

As the back wheel turns on the

ground, the front wheel gets

pushed along too.

So, even though it's not attached to

the chain, it still turns.

And, of course, the front wheel

has another very important job.

Can you guess what it is?

Well, the front wheel is attached to

the handlebars, and if I turn

the handlebars one way, like this,

the front wheel follows.

And if I turn them the other way,

the front wheel goes the same way

and the bike goes that way too.

The front wheel steers the bike,

making sure I can stay safe

and not bump into things.

What was your favourite part about

seeing a bike chain work?

I liked seeing the cogs moving.

Do you remember what you call

this bit of the bike,

the long piece that loops

around the cog?

Yes, that's it,

it's called the bike chain.

Did you hear the sounds all the

parts of the bike made

when I was riding?

CLICKETY-CLACK

And did you see the way the pedals

made the chain move and turn

the bike wheel?

So, the next time you ride your bike

or see someone else

riding theirs, you'll know just

how it works.

But there are so many other fun

things to do outside.

What do you like to do?

I think being outside is

a great place to play with a ball.

There are lots of different

types of balls.

Beach balls to play with in the

sand.

Soft balls to play bat and ball.

Small balls to roll along

the ground.

BOING

Balls to kick.

But one of my favourite games is

catch.

And all you need for that is

a tennis ball.

Tennis balls can be all sorts of

different colours and they're

nice and fluffy, but do you know how

a tennis ball is made?

Let's find out.

The life of a tennis ball

starts here...

in a tennis ball factory.

They make thousands of tennis balls

here and they come in all

sorts of different colours.

There are orange ones, pink ones,

green ones and, of course,

my favourite, yellow and red ones.

I'm going to show you where

it all starts.

This is a big block of rubber,

and rubber is

a stretchy material that's used to

make lots of

different things like...

the tyres on a bicycle,

the sole

of your shoe, or even a tennis ball.

And rubber actually comes from the

inside of a rubber tree.

And it's sent to factories just like

this one to be turned into

lots of different things.

POPS AND CRACKS

When that big block of rubber gets

put on this hot rolling machine

it turns black.

But how does that become

a tennis ball?

This is Andy.

He works at the factory and he's

going to mix up the rubber

with some special ingredients to

make it really strong and bouncy.

It makes lots of dust.

It's like it's snowing inside.

Ha-ha!

Let's go see what happens next.

Andy's now adding his special

ingredient to the black rubber.

It makes it stretchy like dough.

It's a bit noisy, isn't it?

MACHINE HUMS

Thank you.

Wow.

So, this is what it looks like once

it comes off the machine.

Doesn't look much like a ball yet,

does it?

Rubber is very soft and bendy.

And once Andy has fed those rolls of

rubber into the machine,

inside it's being squished together

and pushed through a small hole.

This turns the rubber into

something called nuggets.

And this is what they look like,

just the right amount of rubber to

make half a tennis ball.

So, two nuggets will make one ball.

When the rubber nuggets have cooled

down, they're lined up in

a big tray called a mould.

This machine looks like a big face,

doesn't it?

You can see two eyes,

a nose and a big mouth.

And, look, our nuggets are being fed

into the mouth of the machine.

Can you guess what happens to

the nuggets next?

Inside the machine the nuggets get

pressed together by a heavy weight.

It weighs the same as three lorries.

How heavy is that?!

And can you hear the sound?

It sounds like a stream train

just chugging along.

HISS

Let's see what all that

weight on the mould

has done to the rubber nuggets.

Wow! For the first time they're

actually starting to look

like balls.

But they're half balls at the moment

and you can't play anything

with that,

so, we need to stick them together.

And this machine will do just the

job. It's another pressing machine.

As the machine heats the balls,

it makes the rubber soft and

sticky so that the two sides are

glued together.

Look! Here we have our tennis ball.

BOING

Look how bouncy it is.

Do you think it's finished?

Not quite, there's one final step

and that is it's

brightly-coloured fuzzy coat.

And this is where they put

their coats on.

The coats arrive at the factory like

this, in two pieces of material.

It feels all fuzzy.

Do you know what animal this

material comes from?

Well, I've brought

a special camera with me.

It's like a microscope, which makes

really small things look really big.

Let's use it on our fuzzy material

to see if it can help you

guess what animal this comes from.

Whoa, look at that!

You can see every tiny part of

the cloth.

And those little stringy bits

are called fibres and they help the

ball to fly through the air.

Ah, I think I've seen something

like this before.

Have you guessed the animal?

Yep, it's a sheep.

BAA!

This material comes from wool,

which you get from a sheep's coat.

Our ball has now been covered in

glue and it's time to put its

woolly coat on.

The coat comes in two pieces and

they fit together rather like

a jigsaw.

And there we go, the ball is almost

finished. But the glue around

the edges is still quite rough and

we want it to be nice and smooth.

So, it needs to go

into the last machine.

The balls go into the final press,

which melts the glue and

makes it smooth.

And here we have our finished ball.

The glue is smooth and flat

and that fuzzy material is

all soft and fluffy.

Now it's time to play with it.

What was your favourite part of

making a tennis ball?

Can you remember what tennis

balls are made of?

That's right, rubber and it comes

from inside a rubber tree.

Did you hear the sound the machine

made when it squashed the

rubber nuggets into half balls?

HISS

It sounded like a steam train.

And did you see what the cloth on

the tennis ball looked like

when we filmed it with my

special camera?

Look at all those fluffy little

fibres. They come from a

sheep's woolly coat.

BAA!

So, the next time you play with a

ball or go for a ride on a bike,

you can tell everybody you know just

how it was made and how it works.

Anyone for a game of catch?

See you next time.