05x17 - GT Sledding, Golf Ball and High Bar

[bunniefuu]

[Dallas off-screen] This
is the Science of Stupid.

Yes, this is the show that takes a
beaker full of science,

mixes in a bucket full of stupidity and
steps back to view the results.

We watch and wince and then we use
science to tell you what happened

and where it all went wrong.

With the help of such scientific
principles as torque,

stability and reaction force.

So get ready and grab a hold, this is
going to be a bumpy ride.

It's the Science of Stupid.

In this show we'll be looking at
Newton's second law of motion,

rotation and the
square cube law.

But first this.

I remember when I got my first set of
wheels, well wheel actually.

I'd failed my driving test so
my first ride

was a unicycle but what a sweet
ride it was.

Ah the memories.

But I don't think
she'll want to remember that.

And if he could forget that
then he probably would.

It might be hard to imagine after
watching that,

but unicycle tricks are
fun and

for me the go-to trick
has always been the spin.

When you bunny hop up and
rotate the unicycle under you.

But spins aren't simple
and science can explain why.

He pedals forwards to build momentum for
his jump,

pushing down creates a
reaction force

to get him in the air.

And he pulls the
unicycle upwards.

He generates angular velocity
to rotate it under him

before bringing his
feet back down for landing,

keeping his center of mass over the
wheel to stay stable.

But before you get yourself
into a spin,

remember that whenever you're on a
unicycle

you need to ensure that you're able to
maintain both side to side

and front to back stability.

That is basic stuff.

So rule one is
stability is very important,

which I think
he realizes now.

Our unicyclist completed two turns but
he lost his forwards/backwards stability

which meant the only way
he was going was down.

Maybe this guy
will fair better.

Eh, maybe not.

He did achieve the rapid angular
acceleration needed

but didn't decelerate the

unicycle quickly enough to get
his feet back on the pedals.

And that meant getting
cozy with the car park.

There are three essentials
when practicing your spin,

persistence, good technique.

And not doing it right
next to the fish pond.

This is a text book illustration of the
need to generate a large enough jump

and fast rotation to
complete a spin successfully.

And the importance of
location, location, location.

Even when you've got the skills to mix
it up your center of mass still needs to

be in the right place.

By kicking out he upped the difficulty

as his center of mass wasn't over the
top of

the unicycle when
he moved back in.

And that meant it wasn't his foot that
ended up on the pedal.

Challenging yourself
in life is good.

Except when that happens.

When he landed on the seat it acted as a
lever and flipped the unicycle.

Well we all know science is about using
your head, but probably not like that.

Ten pin bowling is right up my alley,

it's an hour of sitting around
occasionally

interrupted by a few
seconds of activity.

And even though I spend most of my time
in the gutter,

occasionally I get a strike.

A little bit like this guy.

But if you don't have a helmet to throw
you can always use yourself.

Oh I think you've dropped your
sunglasses there, yeah just there.

Human bowling is the sport where you
replace the ball and pins

with actual people,

but before you rope in some of your
friends for a quick ten frames,

there's a little bit
of science to consider.

When sliding, frictional forces will
absorb some of his momentum,

but less likely so if there
is a lubricant like water.

The faster he goes the more momentum he
will have

and when he collides with someone

he will transfer
some of it to them.

Because he's on the ground,

he'll hit below their center of mass
which means that

instead of just translating them
forwards, he will also rotate them,

often causing them
to land on him.

So its all about the transfer of
momentum, rotation and translation.

And the more momentum you transfer, the
faster the rotation will be.

Sounds more complicated
than I remembered.

She is going for
it and they got it.

But so did she.

By running quickly our human bowling
ball managed to transfer her momentum

into a textbook rotation.

For beginners it's
best to start with pins.

And a refresher in how
water can reduce friction.

A big run up resulted in lots of
momentum

but most was lost when he
slipped and slid.

[man] I nailed my head.

[Dallas off-screen] Yes but
unfortunately not the pins.

A slope adds jeopardy.

[man] Bring it on!

[Dallas off-screen]
Jeopardy and pain.

The slope and the snow's low coefficient
to friction allowed him to build lots of

momentum, crashing into
his friend's center of mass

which causes a
translation with an extra twist.

So if you don't want to be a human
skittle,

it's simply a matter of a well
timed jump.

After which you can continue with your
very important phone call.

Quick reactions enabled him to avoid the
impact and the substantial rotation

that would have followed.

Who said reaction times are reduced when
you're on the phone?

You have to play the ball where it lies,
but what science is this winter golfer

about to show us?

[Dallas off-screen] No one likes to drop
a shot, but did you guess what science

this golfer was
about to demonstrate?

Exactly, it's impact force.

The combination of our golfer's
angular momentum

and the ice's low coefficient to

friction caused him to slip.

And because he hits the
ice with considerable speed,

he exerted a
large impact force

which overcame the
ice's material strength.

I think that's what they call a hole in
one and a very good reason

why you shouldn't play on ice.

I think we can
all agree on one thing,

having your car break
down can be very frustrating,

especially as mine always
seems to do it when I'm on

the school run in my pajamas.

And let me tell you, pushing a Sedan in
your slippers isn't easy,

but I suppose it
could be worse.

Like this.

[man] Go up, go up!

[Dallas off-screen] Oh I'm
sure that'll just buff out.

And this just seems
like a bad idea.

Though this guy seems to have
everything under control.

But if you find yourself in the
unfortunate position of

needing to give your car a push, we can
help out a bit.

Not with the actual pushing obviously
but with the science to get you moving.

He leans forward so his center of mass
is in front of his feet

and relies on the

static friction between his feet and the
ground to give him traction.

He applies pushing
force to the car.

Newton's second law of motion

states that the heavier the car and the
greater the

desired acceleration, the
larger the force needs to be.

And once the vehicle starts to
move,

he needs to adjust the
force or the vehicle could

accelerate away too quickly.

Well that actually all
seems rather simple in theory,

but as we know the reality is
often very different.

Because if you do manage to get the car
moving, there are still pitfalls.

Literally.

This guy's got a great stance

and plenty of static friction between
foot and ground,

so the car was on
its way in no time.

And thanks to
gravity, so was he.

Once something gets moving, if you don't
adjust the force, then that can happen.

Once the cart's moved, he didn't adjust
his positioning

and because his center of mass
was already angled

about 19 degrees in front of his feet,

gravity acted, quite quickly.

This kid is clearly too young to drive
and to make things worse he's speeding.

[woman] Oh my God!

[Dallas off-screen] And that is why you
shouldn't try this at home.

A hill and a push means this little
stunt man

built up a lot of momentum and
too much

speed on the ramp equaled too much
launch velocity

and that's why I always recommend
wearing a belt

both inside and outside the vehicle.

[laughing]

[Dallas] Okay listen up class because
it's time for today's science lesson.

This is the part of the show

where we take a scientific principle
apart to see if we

can put it back together again.

So who can tell me what these three
things are demonstrating?

This clumsy poser.

This beach babe.

[man] Oh ****!

[Dallas off-screen] And this
unfortunate weather girl.

[woman] ...and there's
no signs to stop...

[Dallas] If you guessed square cube law
then you would be correct,

well done you.

But just what on
earth does it mean?

As they fall the smaller balloon has let
weight and experiences proportionally

more drag.

If an object is scaled up in size, it's
volume will increase more quickly in

proportion to
its surface area.

The larger balloon's weight

is proportionally greater than the drag
slowing it down,

so it hits with more force.

And smaller objects are not only more
effected by drag,

they tend to be stronger
relative to their weight,

have better power to weight ratio

and change
temperature more quickly.

So that's the science, let's see who's
been paying attention.

Question one,

what effect does the ratio of surface
area to volume have on an object?

Let's see.

[screams]

[Dallas off-screen] Ah.

The small snowball has a large surface
area in proportion to it's volume,

so it was slowed
quickly by drag.

Although not as quickly as
it was slowed by her face.

Of course if you scale up a snowball

then the volume will increase
proportionally faster

than its surface area, decreasing how
much its affected by drag.

[man] Come on!

[man] You ready?

[Dallas off-screen]
So add a hill.

[man off-screen] Oh my God!

[Dallas off-screen]
And that'll happen.

[man] He's hurt, he is hurt!

[Dallas off-screen] It's always nice to
have sympathetic friends.

Question two, when something is scaled
down, what affect does it have

on its power to weight ratio?

Any ideas?

Well that looked painful.

As this remote control car is small,

it has a higher power to weight ratio
than a normal

car, which means a surprising
amount of acceleration.

And a trip to the park this kid won't
forget any time soon.

[man] Did you just whack
that little kid in the ba*ls?

[Dallas off-screen]
Yes he did!

And now for our final question, how does
the square cubed law

affect heat transfer?

Ah, now here's a guy trying a
variation of barbecuing

where he's dropping a frozen turkey

into a vat of boiling oil over an open
flame, so nothing to worry about here.

See!

[woman] Woah!

Holy mackerel,
good thing we're inside!

[Dallas off-screen] The water in the
frozen turkey

rapidly vaporizes into steam, dispersing
the oil into small droplets

with a proportionally larger
surface area.

When they come into contact
with the flame,

they quickly heat to their ignition
point.

[woman] It's going
to be delicious now.

[Dallas off-screen] I hope they like
their turkey on the crispy side.

Class dismissed.

[Dallas] When I was younger, I always
used to daydream

about ways to make myself taller and
then one day I had an epiphany,

why not just stand on a chair?

Do it right and
you'll hit the highs.

Do it wrong and
you'll hit the floor.

A swivel chair
will add complexity

as will a handstand.

[man] Yi-ah! Ooh! Ooh!

[Dallas off-screen] In the UK alone,


are hospitalized a year from chair
related incidents,

so if you don't want to become a
statistic then you better pay

attention to this science.

Standing safely on a chair

requires him to try and make his base of
support as wide as

possible and he can do
this by spreading his feet.

His stability will be increased if he
lowers his center of gravity and makes

sure it remains over
his base of support.

However, should he lean too far to one
side, he might rotate over.

He needs to ensure the chair

is on a surface which provides
sufficient friction between

the two, otherwise
the chair could slip.

And of course as any fans of
chair standing already know,

you also need to consider your

choice of chair as this
can impact your stability.

Just like Leo and Kate, this guy's
feeling on top of the world.

He's definitely flying
high, but what goes up.

[man] Ow!

[Dallas off-screen]
Must come down, painfully.

The front of that chair isn't above its
base of support,

so when he stands on it,

it tips forward throwing his
legs against the wall

before he has a titanic fall.

[man] Ow!

[Dallas off-screen] A soldier's training
is never done,

even when he's not on duty it's
essential to keep the same focus,

skill and precision.

But that unfortunately
had none of those things.

By stretching to full height, he raised
his center of gravity

and reduced his stability.

When he lifted his hand, it
unbalanced him

and moved his base of support out
from under

his center of gravity.

This guy is cool, who
wouldn't want to be him?

And I'm sure he's all over his
scientific principals too.

[man] Woo hoo! Oh!

[Dallas off-screen]
Oh perhaps not.

This funky dancer forgot about friction

and with not enough between chair and
ground

it slid and gravity
applied a turning force.

It doesn't matter how cool you think you
are, if you don't know your science

it's gonna hurt.

I love throwing things,
parties, tantrums, my voice.

The only thing I'm not good at throwing
is ba*ls and that's because throwing

isn't as simple as it seems.

As he's just demonstrated.

This guy is great
at throwing though.

But the crowd
probably wish he wasn't.

Animals have evolved into many different
forms, so if they need to throw

they can execute this task in a
variety of ways.

To throw, you transfer momentum into an
object using arm motion and hand grip.

It requires motor coordination to
release at the correct angle

and sufficient velocity
to reach the target.

Animals like primates can use
an underarm pendulum swing,

this transfers the
weight of the object

forwards as the
straight arm swings.

Other animals have evolved to
throw differently,

elephants have highly
flexible trunks

which act as long levers capable of
providing sufficient force for throwing.

And by using their necks as levers,

birds can use their beaks to grip and
throw.

An animal's ability to grip effectively
will vary greatly depending

on their biomechanics.

Elephants are known for their dexterous
trunks, long memories and for being

particularly choosy about what
angle they're photographed from.

His trunk is a long lever,

this allows him to generate the
necessary accuracy and

force to hit his target.

Next time, make sure
you're getting his good side.

[woman] Eric, no!

[Dallas off-screen] But the shorter
the lever,

the more difficult it is to throw.

[woman] Eric, no!

Stop it.

[Dallas off-screen] But attitudes can
often overcome obstacles

especially a bad one.

[woman] Naughty bird.

[Eric] Naughty bird.

[Dallas off-screen] Yeah, naughty and
increasingly expensive.

Right so that's it for now

and just in case you've been
inspired by anything you've

seen here today, don't be.

And here's a reminder of why.

[music plays through credits]