0:00:03 > 0:00:07# There are lots of things all around us
0:00:07 > 0:00:10# Exciting things that surround us
0:00:10 > 0:00:13- # But how does it work?- Do you know?
0:00:13 > 0:00:17- # How is it made?- Do you know?
0:00:17 > 0:00:20# Things that go up Things that go down
0:00:20 > 0:00:24# Things that go pop Things that go round
0:00:24 > 0:00:27# With special cameras to show you inside
0:00:27 > 0:00:30# It's going to be a big surprise
0:00:30 > 0:00:34- # But how does it work?- Do you know?
0:00:34 > 0:00:37- # How is it made?- Do you know?
0:00:37 > 0:00:40- # Do you know?- Let's find out!- #
0:00:48 > 0:00:53Hello, I'm Maddie, and today I've come to the park to ride my bike.
0:00:53 > 0:00:55Have you learned how to ride a bike?
0:00:55 > 0:00:58Now, they say once you've learned, you never forget,
0:00:58 > 0:01:02but do you know how a bike works?
0:01:02 > 0:01:04Let's find out.
0:01:10 > 0:01:15When I ride my bike, I put my hands on the handlebars, like this,
0:01:15 > 0:01:17and I put my feet on the pedals.
0:01:17 > 0:01:21And you can see that as I push the pedals, the wheels go round too,
0:01:21 > 0:01:24and this is what makes the bike move.
0:01:24 > 0:01:28But how do the pedals make the wheels go round?
0:01:28 > 0:01:32Well, that's thanks to something called the chain.
0:01:37 > 0:01:40The chain is this large metal loop here.
0:01:40 > 0:01:44It's made of lots of smaller pieces of metal that are fixed together,
0:01:44 > 0:01:46called links.
0:01:46 > 0:01:50The chain goes round this large metal cog, which is attached
0:01:50 > 0:01:54to the pedals, and you can follow it back to the smaller metal cog,
0:01:54 > 0:01:56which is attached to the wheel.
0:01:56 > 0:02:00But to see how the chain makes the bike move, we need to take
0:02:00 > 0:02:02a closer look.
0:02:02 > 0:02:04RING RING
0:02:04 > 0:02:07When you push the pedals with your feet, they turn the big cog in
0:02:07 > 0:02:11the middle of the bike round and round.
0:02:11 > 0:02:18The big cog has teeth all around the edge and the chain links have
0:02:18 > 0:02:21little holes in.
0:02:21 > 0:02:24The holes hook on to the teeth.
0:02:24 > 0:02:30When the pedals turn the big cog, the teeth pull the chain around too.
0:02:30 > 0:02:34At the other end of the chain is a smaller cog.
0:02:34 > 0:02:37This one is attached to the back wheel.
0:02:37 > 0:02:41As the chain is pulled around the big cog by the pedals,
0:02:41 > 0:02:44the holes hook on to the teeth on the little cog
0:02:44 > 0:02:49which turns the back wheel and pushes the bike along.
0:02:49 > 0:02:53This means we can go zooming along on our bikes.
0:02:53 > 0:02:55Wheee! RING RING
0:02:55 > 0:02:57How clever is that?
0:02:57 > 0:03:00I don't know about you, but I want to see all of that
0:03:00 > 0:03:01going on for real.
0:03:01 > 0:03:04So, I'm going to go on another ride on my bike,
0:03:04 > 0:03:08but so you can see the chain working close up in action,
0:03:08 > 0:03:11I've got my special little camera here.
0:03:11 > 0:03:14Let's attach it to the bike.
0:03:18 > 0:03:19Let's go.
0:03:24 > 0:03:28Can you see my feet on the pedals turning the big cog?
0:03:29 > 0:03:33And, look, can you see the chain moving and the little cog
0:03:33 > 0:03:36that's turning the back wheel?
0:03:38 > 0:03:41Can you hear the sound of all the parts working together?
0:03:41 > 0:03:45GEARS CLICK
0:03:45 > 0:03:50It's like clickety-click, clickety-click, clickety-click.
0:03:52 > 0:03:55Brilliant. I love riding my bike.
0:03:55 > 0:03:57But what about the front wheel?
0:03:57 > 0:04:01The front wheel isn't attached to a chain so how does it move?
0:04:03 > 0:04:07As the back wheel turns on the ground, the front wheel gets
0:04:07 > 0:04:09pushed along too.
0:04:09 > 0:04:14So, even though it's not attached to the chain, it still turns.
0:04:14 > 0:04:18And, of course, the front wheel has another very important job.
0:04:18 > 0:04:20Can you guess what it is?
0:04:20 > 0:04:25Well, the front wheel is attached to the handlebars, and if I turn
0:04:25 > 0:04:30the handlebars one way, like this, the front wheel follows.
0:04:30 > 0:04:34And if I turn them the other way, the front wheel goes the same way
0:04:34 > 0:04:36and the bike goes that way too.
0:04:38 > 0:04:42The front wheel steers the bike, making sure I can stay safe
0:04:42 > 0:04:44and not bump into things.
0:04:51 > 0:04:55What was your favourite part about seeing a bike chain work?
0:04:55 > 0:04:58I liked seeing the cogs moving.
0:05:00 > 0:05:03Do you remember what you call this bit of the bike,
0:05:03 > 0:05:07the long piece that loops around the cog?
0:05:07 > 0:05:11Yes, that's it, it's called the bike chain.
0:05:11 > 0:05:14Did you hear the sounds all the parts of the bike made
0:05:14 > 0:05:15when I was riding?
0:05:15 > 0:05:18CLICKETY-CLACK
0:05:22 > 0:05:25And did you see the way the pedals made the chain move and turn
0:05:25 > 0:05:27the bike wheel?
0:05:33 > 0:05:36So, the next time you ride your bike or see someone else
0:05:36 > 0:05:39riding theirs, you'll know just how it works.
0:05:39 > 0:05:43But there are so many other fun things to do outside.
0:05:43 > 0:05:44What do you like to do?
0:05:44 > 0:05:49I think being outside is a great place to play with a ball.
0:05:49 > 0:05:53There are lots of different types of balls.
0:05:53 > 0:05:55Beach balls to play with in the sand.
0:05:55 > 0:05:58Soft balls to play bat and ball.
0:05:59 > 0:06:02Small balls to roll along the ground.
0:06:04 > 0:06:06BOING Balls to kick.
0:06:06 > 0:06:09But one of my favourite games is catch.
0:06:09 > 0:06:12And all you need for that is a tennis ball.
0:06:12 > 0:06:16Tennis balls can be all sorts of different colours and they're
0:06:16 > 0:06:21nice and fluffy, but do you know how a tennis ball is made?
0:06:21 > 0:06:23Let's find out.
0:06:28 > 0:06:32The life of a tennis ball starts here...
0:06:32 > 0:06:33in a tennis ball factory.
0:06:33 > 0:06:37They make thousands of tennis balls here and they come in all
0:06:37 > 0:06:39sorts of different colours.
0:06:39 > 0:06:43There are orange ones, pink ones, green ones and, of course,
0:06:43 > 0:06:46my favourite, yellow and red ones.
0:06:47 > 0:06:50I'm going to show you where it all starts.
0:06:50 > 0:06:54This is a big block of rubber, and rubber is
0:06:54 > 0:06:57a stretchy material that's used to make lots of
0:06:57 > 0:06:59different things like...
0:06:59 > 0:07:02the tyres on a bicycle,
0:07:02 > 0:07:06the sole of your shoe, or even a tennis ball.
0:07:06 > 0:07:11And rubber actually comes from the inside of a rubber tree.
0:07:13 > 0:07:17And it's sent to factories just like this one to be turned into
0:07:17 > 0:07:18lots of different things.
0:07:21 > 0:07:23POPS AND CRACKS
0:07:23 > 0:07:27When that big block of rubber gets put on this hot rolling machine
0:07:27 > 0:07:30it turns black.
0:07:30 > 0:07:33But how does that become a tennis ball?
0:07:35 > 0:07:36This is Andy.
0:07:36 > 0:07:40He works at the factory and he's going to mix up the rubber
0:07:40 > 0:07:45with some special ingredients to make it really strong and bouncy.
0:07:45 > 0:07:46It makes lots of dust.
0:07:46 > 0:07:50It's like it's snowing inside.
0:07:50 > 0:07:52Ha-ha!
0:07:54 > 0:07:56Let's go see what happens next.
0:07:59 > 0:08:03Andy's now adding his special ingredient to the black rubber.
0:08:03 > 0:08:07It makes it stretchy like dough.
0:08:07 > 0:08:09It's a bit noisy, isn't it?
0:08:09 > 0:08:11MACHINE HUMS
0:08:11 > 0:08:13Thank you.
0:08:13 > 0:08:14Wow.
0:08:14 > 0:08:19So, this is what it looks like once it comes off the machine.
0:08:19 > 0:08:22Doesn't look much like a ball yet, does it?
0:08:22 > 0:08:26Rubber is very soft and bendy.
0:08:26 > 0:08:31And once Andy has fed those rolls of rubber into the machine,
0:08:31 > 0:08:36inside it's being squished together and pushed through a small hole.
0:08:40 > 0:08:44This turns the rubber into something called nuggets.
0:08:45 > 0:08:47And this is what they look like,
0:08:47 > 0:08:52just the right amount of rubber to make half a tennis ball.
0:08:52 > 0:08:55So, two nuggets will make one ball.
0:08:55 > 0:08:59When the rubber nuggets have cooled down, they're lined up in
0:08:59 > 0:09:01a big tray called a mould.
0:09:01 > 0:09:04This machine looks like a big face, doesn't it?
0:09:04 > 0:09:08You can see two eyes, a nose and a big mouth.
0:09:08 > 0:09:13And, look, our nuggets are being fed into the mouth of the machine.
0:09:15 > 0:09:20Can you guess what happens to the nuggets next?
0:09:20 > 0:09:26Inside the machine the nuggets get pressed together by a heavy weight.
0:09:26 > 0:09:30It weighs the same as three lorries. How heavy is that?!
0:09:30 > 0:09:32And can you hear the sound?
0:09:32 > 0:09:36It sounds like a stream train just chugging along.
0:09:36 > 0:09:37HISS
0:09:41 > 0:09:44Let's see what all that weight on the mould
0:09:44 > 0:09:47has done to the rubber nuggets.
0:09:47 > 0:09:50Wow! For the first time they're actually starting to look
0:09:50 > 0:09:52like balls.
0:09:52 > 0:09:56But they're half balls at the moment and you can't play anything
0:09:56 > 0:09:59with that, so, we need to stick them together.
0:10:01 > 0:10:06And this machine will do just the job. It's another pressing machine.
0:10:10 > 0:10:14As the machine heats the balls, it makes the rubber soft and
0:10:14 > 0:10:18sticky so that the two sides are glued together.
0:10:18 > 0:10:21Look! Here we have our tennis ball.
0:10:21 > 0:10:24BOING Look how bouncy it is.
0:10:24 > 0:10:26Do you think it's finished?
0:10:26 > 0:10:30Not quite, there's one final step and that is it's
0:10:30 > 0:10:32brightly-coloured fuzzy coat.
0:10:35 > 0:10:38And this is where they put their coats on.
0:10:38 > 0:10:43The coats arrive at the factory like this, in two pieces of material.
0:10:43 > 0:10:45It feels all fuzzy.
0:10:45 > 0:10:49Do you know what animal this material comes from?
0:10:49 > 0:10:52Well, I've brought a special camera with me.
0:10:52 > 0:10:58It's like a microscope, which makes really small things look really big.
0:10:58 > 0:11:02Let's use it on our fuzzy material to see if it can help you
0:11:02 > 0:11:04guess what animal this comes from.
0:11:07 > 0:11:08Whoa, look at that!
0:11:08 > 0:11:12You can see every tiny part of the cloth.
0:11:12 > 0:11:16And those little stringy bits are called fibres and they help the
0:11:16 > 0:11:19ball to fly through the air.
0:11:19 > 0:11:22Ah, I think I've seen something like this before.
0:11:22 > 0:11:25Have you guessed the animal?
0:11:25 > 0:11:26Yep, it's a sheep.
0:11:26 > 0:11:28BAA!
0:11:28 > 0:11:33This material comes from wool, which you get from a sheep's coat.
0:11:34 > 0:11:38Our ball has now been covered in glue and it's time to put its
0:11:38 > 0:11:40woolly coat on.
0:11:40 > 0:11:43The coat comes in two pieces and they fit together rather like
0:11:43 > 0:11:44a jigsaw.
0:11:51 > 0:11:56And there we go, the ball is almost finished. But the glue around
0:11:56 > 0:12:00the edges is still quite rough and we want it to be nice and smooth.
0:12:00 > 0:12:04So, it needs to go into the last machine.
0:12:04 > 0:12:08The balls go into the final press, which melts the glue and
0:12:08 > 0:12:09makes it smooth.
0:12:09 > 0:12:13And here we have our finished ball. The glue is smooth and flat
0:12:13 > 0:12:18and that fuzzy material is all soft and fluffy.
0:12:18 > 0:12:20Now it's time to play with it.
0:12:22 > 0:12:26What was your favourite part of making a tennis ball?
0:12:27 > 0:12:31Can you remember what tennis balls are made of?
0:12:32 > 0:12:36That's right, rubber and it comes from inside a rubber tree.
0:12:39 > 0:12:43Did you hear the sound the machine made when it squashed the
0:12:43 > 0:12:45rubber nuggets into half balls?
0:12:45 > 0:12:49HISS
0:12:49 > 0:12:51It sounded like a steam train.
0:12:53 > 0:12:57And did you see what the cloth on the tennis ball looked like
0:12:57 > 0:13:00when we filmed it with my special camera?
0:13:00 > 0:13:04Look at all those fluffy little fibres. They come from a
0:13:04 > 0:13:06sheep's woolly coat.
0:13:06 > 0:13:07BAA!
0:13:11 > 0:13:15So, the next time you play with a ball or go for a ride on a bike,
0:13:15 > 0:13:20you can tell everybody you know just how it was made and how it works.
0:13:20 > 0:13:22Anyone for a game of catch?
0:13:22 > 0:13:24See you next time.
0:13:27 > 0:13:31# There are lots of things all around us
0:13:31 > 0:13:34# Exciting things that surround us
0:13:34 > 0:13:37- #- But how does it work?- Do you know?
0:13:37 > 0:13:41- #- How is it made?- Do you know?
0:13:41 > 0:13:44- # Do you know?- Let's find out!- #