0:00:05 > 0:00:08# If you've got a question and you don't know where to go
0:00:08 > 0:00:12# Ask Nina for some help cos she's got a science show
0:00:12 > 0:00:15# She makes sense of her senses while helping all her fans
0:00:15 > 0:00:17# By doing her experiments with potions and with bangs
0:00:17 > 0:00:19- # Touch your tongue - Tongue!
0:00:19 > 0:00:20- # Fingers - Fingers!
0:00:20 > 0:00:23- # Eyes- Eyes! - Ears- Ears!- Nose- Nose!
0:00:23 > 0:00:26# Nina and the Neurons find out what you need to know
0:00:26 > 0:00:29# Nina and the Neurons find out what you need to know
0:00:29 > 0:00:32# Luke, he helps us with our eyes and Felix with our touch
0:00:32 > 0:00:35# Ollie sniffs out smells and Belle, she hears so much
0:00:35 > 0:00:38# Bud is Ollie's brother He helps us with our taste
0:00:38 > 0:00:41# They're Nina's little neurons and they're coming to your place!
0:00:41 > 0:00:43- # Touch your tongue - Tongue!
0:00:43 > 0:00:44- # Fingers - Fingers!
0:00:44 > 0:00:47- # Eyes- Eyes! - Ears- Ears!- Nose- Nose!
0:00:47 > 0:00:50# Nina and the Neurons find out what you need to know
0:00:50 > 0:00:53# Nina and the Neurons find out what you need to know
0:00:53 > 0:00:54# Oh, yeah! #
0:00:56 > 0:00:59There! 33 centimetres. Perfect!
0:00:59 > 0:01:01Oh, hello!
0:01:01 > 0:01:04I'm measuring my cupboard door, because I need a new one.
0:01:04 > 0:01:07This measuring tape is very handy.
0:01:07 > 0:01:09Now I know exactly what size I need.
0:01:09 > 0:01:10ALARM BEEPS
0:01:10 > 0:01:14Oh! I hear a beep, I see a flash - I wonder what they're going to ask.
0:01:20 > 0:01:22BOTH: Hi, Nina!
0:01:22 > 0:01:24Hi, there!
0:01:24 > 0:01:28We've got a question for you. How does a seat belt in a car work?
0:01:28 > 0:01:33That's a great question. How does a seat belt in a car work?
0:01:33 > 0:01:37Well, a seat belt helps keep us safe when we're in a car.
0:01:37 > 0:01:43- Why not come to the workshop and check it out?- See you soon - bye!
0:01:43 > 0:01:44Bye!
0:01:44 > 0:01:49Well, I'll need some help to answer this one and I know just who to ask.
0:01:49 > 0:01:51OK, Neurons, time to get to work.
0:02:08 > 0:02:10ALL: Neurons at the ready, Nina!
0:02:10 > 0:02:15OK. Today's question is, how does a seat belt in a car work?
0:02:15 > 0:02:20Which neuron will be most useful in helping us find the answer?
0:02:20 > 0:02:23- ALL: Me! Me, me, me! - Me!
0:02:23 > 0:02:25Will it be fabulous Felix?
0:02:25 > 0:02:30I can help so very much, if you need the sense of touch.
0:02:30 > 0:02:31Will it be beautiful Belle?
0:02:31 > 0:02:36I send messages to brain from ear. If there's a sound, I'll help you hear.
0:02:36 > 0:02:40- Will it be lovely Luke?- For looking and seeing, day or night,
0:02:40 > 0:02:43I'll help you with your sense of sight.
0:02:43 > 0:02:45Will it be awesome Ollie?
0:02:45 > 0:02:49If it's pongy or whiffy but you can't tell, I'll help your sense of smell.
0:02:49 > 0:02:51Or will it be baby Bud?
0:02:51 > 0:02:53Sour, salty, bitter or sweet -
0:02:53 > 0:02:56I'm your taste buddy whenever you eat.
0:02:59 > 0:03:02- It's Felix!- Oh!
0:03:03 > 0:03:05NEURONS: Go, Felix! Go, Felix!
0:03:05 > 0:03:07Go, Felix! Go, Felix!
0:03:07 > 0:03:09Go, Felix! Go, Felix!
0:03:09 > 0:03:11- Go, Felix!- Marvellous!
0:03:11 > 0:03:14A little touch can mean so much, Nina.
0:03:14 > 0:03:18Today's question is, how does a seat belt in a car work?
0:03:18 > 0:03:22Because a seat belt is something we feel against us when it's on,
0:03:22 > 0:03:26Felix will help us. But standby, Neurons, I may need all of you!
0:03:26 > 0:03:30Right, I need to get the workshop ready before the Inventors arrive.
0:03:32 > 0:03:35Jed and Ryan want to find out all about seat belts -
0:03:35 > 0:03:40long seat belts, strong seat belts, keep-you-nice-and-safe seat belts.
0:03:40 > 0:03:45So today, for one day only, Jed and Ryan become the Inventors!
0:03:47 > 0:03:50- Hi, guys. - BOTH: Hi, Nina.
0:03:50 > 0:03:53Thanks for coming along today and for your great question -
0:03:53 > 0:03:57how does a seat belt work? Why do you want to know that?
0:03:57 > 0:04:01Any time we go in a car, we have to put our seat belts on
0:04:01 > 0:04:03and we wanted to know how they work.
0:04:03 > 0:04:07Well, you should always wear a seat belt in a car.
0:04:07 > 0:04:10I happen to have my car here, so put your belts on.
0:04:19 > 0:04:23Well, would you look at that?! The seat belt got really long.
0:04:23 > 0:04:26And listen how it clicks into place, Belle.
0:04:26 > 0:04:27Click-clunk!
0:04:27 > 0:04:32So, you pulled the seat belt out and locked it into place down here.
0:04:32 > 0:04:35- So how does it feel?- It feels fine.
0:04:35 > 0:04:40Look what happens when I pull this seat belt forward really quickly.
0:04:40 > 0:04:43- The seat belt stops.- That's right.
0:04:43 > 0:04:48That's because, if a car brakes suddenly, your body goes forward,
0:04:48 > 0:04:49pulls on the seat belt,
0:04:49 > 0:04:53and the seat belt holds you tightly so you don't hurt yourself.
0:04:53 > 0:04:57Yes, Nina, and that's why we should all wear seat belts in a car.
0:04:57 > 0:05:00They help to keep us safe.
0:05:00 > 0:05:04So we know WHAT a seat belt does, but we don't know HOW.
0:05:04 > 0:05:06Let's go to the workshop and look!
0:05:07 > 0:05:11Over here, we have a seat belt, just like the one in my car,
0:05:11 > 0:05:14but this has been taken apart.
0:05:14 > 0:05:18Taking things apart is my job. It can be dangerous, so don't do it.
0:05:18 > 0:05:21That's right. Nina's been specially trained to do this.
0:05:21 > 0:05:26You could get hurt when you take things apart, so leave it to experts.
0:05:26 > 0:05:30Now, here, this bit is the black seat belt.
0:05:30 > 0:05:32If I pull it, it comes out,
0:05:32 > 0:05:37and if I let it go, it goes back in, just like the one in my car.
0:05:37 > 0:05:40And if I pull it out quickly...
0:05:40 > 0:05:43- It stops!- Yes. Have a look here.
0:05:43 > 0:05:46Now, you see this bit? This is a clutch.
0:05:46 > 0:05:50A clutch stops the seat belt if a car brakes suddenly.
0:05:50 > 0:05:55- But how does it roll back up? - Ah, well, that's a bit different.
0:05:55 > 0:06:00Let me turn this round. There's a bit in here called a spindle.
0:06:00 > 0:06:02The seat belt is wrapped around it.
0:06:02 > 0:06:06If we look inside the spindle, using my Ninacam,
0:06:06 > 0:06:09this is a coil.
0:06:09 > 0:06:13The coil uses something called torsion to wind the belt back in.
0:06:13 > 0:06:17Torsion - what a lovely word. Torsion.
0:06:18 > 0:06:19Ooh!
0:06:19 > 0:06:22Now, I know something else that uses torsion.
0:06:22 > 0:06:25It's like a seat belt but even more exciting.
0:06:25 > 0:06:30- Shall we see another invention in action?- Yeah!- Let's go!
0:06:35 > 0:06:38Hmm. Where do you think we're going today?
0:06:38 > 0:06:43Well, Nina said that torsion helps wind the seat belt back in.
0:06:43 > 0:06:46So what else uses torsion?
0:06:46 > 0:06:50- I haven't got a clue what that could be!- I think we'll soon find out.
0:06:50 > 0:06:52Looks like we've arrived.
0:06:52 > 0:06:57So here we are, guys. We've come to a climbing wall.
0:06:57 > 0:07:02The safety rope the climber uses works just like a seat belt.
0:07:02 > 0:07:07If you look closely, the climber is attached to the safety rope,
0:07:07 > 0:07:11which is connected to the wall. As he climbs higher,
0:07:11 > 0:07:14it gets shorter - like a seat belt when it rolls up.
0:07:14 > 0:07:18If a climber falls, the safety rope comes out really slowly,
0:07:18 > 0:07:23so the climber can come safely down to the bottom.
0:07:23 > 0:07:24Oh! Just like that!
0:07:24 > 0:07:28Now, guys, now you know more about safety ropes,
0:07:28 > 0:07:32- I think you should get some equipment on and have a go!- Yeah!
0:07:38 > 0:07:43That's right, boys. Fingers there, foot there, and up you go!
0:07:49 > 0:07:52That's great, Jed, you're doing a really good job.
0:07:56 > 0:08:00Well done, Ryan. My goodness, take your time!
0:08:05 > 0:08:07Well done, guys. That was great!
0:08:07 > 0:08:11- So did you enjoy that? - It was great fun!
0:08:11 > 0:08:16And because we had our safety rope on, we knew if we fell we'd be safe.
0:08:16 > 0:08:22Right, like we a seat belt keeps us safe by stopping if we move quickly.
0:08:22 > 0:08:25But we still don't know how a seat belt winds back in.
0:08:25 > 0:08:29I think we need to go back and get inventing! Out of those harnesses!
0:08:31 > 0:08:35The seat belt we use today is a fantastic invention.
0:08:35 > 0:08:40- I wonder who actually invented it? - I know that! About 50 years ago,
0:08:40 > 0:08:44an inventor called Nils Bohlin worked for a company that made cars.
0:08:44 > 0:08:48He wanted to come up with a way of making the seat belt
0:08:48 > 0:08:51better and more comfortable.
0:08:51 > 0:08:53He thought and thought and...
0:08:53 > 0:08:59created the first seat belt that went across your lap and your body
0:08:59 > 0:09:01and was easy to use.
0:09:01 > 0:09:06It's been helping keep people safe in cars ever since!
0:09:11 > 0:09:14So, we know that a seat belt uses a clutch
0:09:14 > 0:09:19to help it stop when the car brakes suddenly, and we know it has a coil,
0:09:19 > 0:09:25which winds up the leftover seat belt, and a coil uses torsion.
0:09:25 > 0:09:27What is torsion and how does it work?
0:09:27 > 0:09:31Well, let's get inventing and make our own seat belt to find out.
0:09:31 > 0:09:36The first thing to do is make a coil for our seat belt. I have card here.
0:09:40 > 0:09:44Next, we're going to attach one of these little sticks
0:09:44 > 0:09:47to the end of our piece of card.
0:09:47 > 0:09:50Use sticky tape. Stick this on really well.
0:09:53 > 0:09:57Next, we need to wrap the coil around the stick all the way round.
0:09:57 > 0:10:02And we're going to put it inside our spindle.
0:10:02 > 0:10:06What we've made here is a coil like the one we saw in a real seat belt.
0:10:06 > 0:10:07Do you remember what that coil did?
0:10:07 > 0:10:11Is it the bit that pulls the seat belt back in?
0:10:11 > 0:10:16That's right. Now look here. At the moment, the coil isn't moving.
0:10:16 > 0:10:20This is the shape that it stays best in, but watch this...
0:10:23 > 0:10:25The coil's getting smaller.
0:10:25 > 0:10:29That's right. It's getting tighter and closer together.
0:10:29 > 0:10:33It's a different shape to before, but watch if I let it go.
0:10:34 > 0:10:36Look now!
0:10:36 > 0:10:38It went back to the way it was.
0:10:38 > 0:10:41It turned the tube back round again.
0:10:41 > 0:10:44That's right and this is actually a torsion spring.
0:10:44 > 0:10:49That's really useful because it goes back to the shape it started in.
0:10:49 > 0:10:53It's the pulling it does to get back to its original shape
0:10:53 > 0:10:55that's called torsion.
0:10:55 > 0:10:59We're going to use torsion to make our very own seat belt roll back in.
0:10:59 > 0:11:05Let's get on with it! Put another stick on one end of the seat belt.
0:11:05 > 0:11:08And now I'll take the other end
0:11:08 > 0:11:11and stick it to our spindle.
0:11:13 > 0:11:17Next, we need to wrap the seat belt around the spindle.
0:11:17 > 0:11:22Lovely. Now we're going to put the spindle inside the seat belt holder.
0:11:22 > 0:11:26There we go! Excellent!
0:11:26 > 0:11:31So the spindle is in place, and I can now close the lid.
0:11:32 > 0:11:35Well done, Inventors! We have made the seat belt!
0:11:35 > 0:11:38So let's try it out.
0:11:41 > 0:11:43Good job, Inventors!
0:11:48 > 0:11:52So your question was, how does a seat belt in a car work?
0:11:52 > 0:11:54I think we've answered it.
0:11:54 > 0:11:57We looked inside a seat belt and discovered it has a clutch,
0:11:57 > 0:11:59and the clutch stops the seat belt
0:11:59 > 0:12:06from unwinding when the car brakes suddenly, and we also found a coil.
0:12:06 > 0:12:08The coil is a torsion spring,
0:12:08 > 0:12:12and a torsion spring stays a certain shape until we twist it.
0:12:12 > 0:12:15When we twist it one way
0:12:15 > 0:12:19and let go, it twists back again to the shape it was in before.
0:12:19 > 0:12:24The torsion spring in a seat belt pulls it against our body,
0:12:24 > 0:12:27which helps keep us safe and secure in a car.
0:12:27 > 0:12:31And that's how a seat belt works. Thanks for coming to see me today.
0:12:31 > 0:12:33- Thanks, Nina, bye.- Bye!
0:12:38 > 0:12:40If you want to make the invention,
0:12:40 > 0:12:43go to the Nina section on the CBeebies website.
0:12:43 > 0:12:46That'll give you the instructions.
0:12:46 > 0:12:49Or you may have other ideas of what you want to invent.
0:12:51 > 0:12:54- Bikes!- Cranes!
0:12:54 > 0:12:57- Speakers!- And cars!
0:12:57 > 0:12:59# We all love inventing
0:12:59 > 0:13:03# Whoa-oh-oh-oh-oh Go inventing!
0:13:03 > 0:13:05# We all love inventing
0:13:05 > 0:13:08# Why don't you try it too?
0:13:08 > 0:13:11# Inventions make life easier
0:13:11 > 0:13:13# And help us get things done
0:13:13 > 0:13:15# Go inventing!
0:13:15 > 0:13:18# I always like to take a look
0:13:18 > 0:13:19# At how they work and run
0:13:19 > 0:13:21# Go inventing!
0:13:21 > 0:13:23# We all love inventing
0:13:23 > 0:13:27# Whoa-oh-oh-oh-oh Go inventing!
0:13:27 > 0:13:29# We all love inventing
0:13:29 > 0:13:33# Why don't you try it too? #
0:13:33 > 0:13:35It's been a marvellous day.
0:13:35 > 0:13:38I liked seeing seat belts stop when pulled quickly.
0:13:38 > 0:13:41This means they keep you nice and safe.
0:13:41 > 0:13:45Seat belts really are a wonderful safety invention.
0:13:45 > 0:13:48I've had a fabby day!
0:13:48 > 0:13:52Especially when everyone went up and up and up!
0:13:52 > 0:13:54Oh, I've had a brilliant day!
0:13:54 > 0:13:57That is SUCH a clever invention!
0:13:59 > 0:14:05Our day's been bursting with inventions. See you again soon! Bye!
0:14:05 > 0:14:07Bye!