05x06 - Barefoot Skiing, Trays and Jumping Rivers

[bunniefuu]

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

Yes, this is the show where
a combination of complete

stupidity and complex science collide in
a carnival of carnage.

As our band of bold bozos
challenge the boundaries of

scientific knowledge
so you don't have to.

With their help, we'll
demonstrate the science behind

some key principles such as
Young's modulus, momentum,

and microwave radiation.

There can only be one winner
in the battle between

science and stupidity.

So don't be a loser, get ready
to be educated because this

is the Science of Stupid .

In this show we'll be looking
at redirection of velocity,

gravitational acceleration.

And Newton's third law.

But first, this.

I love a bit of snow.

It's great spending the whole
day sledding or taking hours

building the perfect snowman.

And that's exactly what I
make the kids do while I stay

warm and dry inside.

But when a bit becomes
a bit too much,

snow can be quite problematic.

[Dallas off-screen]
Especially when Newton's

second law of
motion is involved.

[man off-screen] Ohh!

[screams]

Oh my God!

[Dallas off-screen] Oh, knew
I shouldn't have parked there.

What they needed was a couple
of paid professionals to

safely get that snow off
the roof, like these guys.

Uh, hang on, I
want my money back.

Ignore the science and
clearing snow off a roof could

end up being as dangerous
as walking a tight-rope

in a tornado.

But it doesn't need to be.

[Dallas off-screen]
The steeper the roof,

the larger the components
of gravity pulling the

snow down the slope.

This is resisted by the
frictional force between snow

and roof, which is often very
low and by the roof and

snow being frozen together.

Vibrations can break
the frozen bonds,

allowing our man
to clear the snow.

Newton's second law tells
us that if the snow isn't

cleared, the force of its
weight can overcome the

material strength of the roof.

Now that we're down
with the basics,

let's put theory into practice with our
team of ever ready researchers.

First up, breaking the adhesion between
snow and roof.

[grunts]

[Dallas off-screen]
Well, that worked!

The vibrations from the shovel
were enough to break any

adhesion between
snow and roof.

When it falls, due to gravity,
the force from its weight and

momentum is more than enough
to clear the snow from the

roof, along with him.

This is an
unconventional technique.

But it is both effective
and entertaining.

The impact force from the
backpack is successful in

breaking up the snow and
gravity direct it downwards,

in a very chilly way.

If you have a make-shift roof,
clearing the snow from it

should be fairly easy.

[grunts]

Told you.

When he cuts the string, the
whole roof comes down due to

the weight of the snow.

And as Newton's
second law states,

the greater an object's mass,
the greater the force it will

exert when it
accelerates on the roof.

[grunts]

And onto him.

Of course, some people just
can't be bothered to do

anything at all.

But while this might
seem like an easy option.

It really isn't.

[man] I got that on video.

[Dallas] Ah, jumping behind the
wheel of a car and going for a

drive is one of life's
simple pleasures.

But for some people, getting out of a
car is a little less joyful.

[Dallas off-screen] Common
sense dictates that getting

out of a vehicle is most successful when
the vehicle is stationary.

Something our friend here
has learnt the hard way.

If you do it right,
it should be easy.

But with bumper cars,
the clue is in the name.

Getting out of a vehicle
shouldn't be that complicated.

But as we know, when
scientific principles such as

friction and turning
force come into play,

things can get tricky.

[Dallas off-screen] When
he exits the vehicle,

he needs to be careful that
his center of mass does not

move outside of his base of
support otherwise gravity will

make him topple.

If his foot is outside the
vehicle and in contact with

the ground, then
friction is acting on it.

But as it moves
with the vehicle,

his center of mass has
momentum which can combine

with the frictional force at
his feet to create a turning

effect that rotates him over.

Of course, any time you
attempt to get out of a moving

vehicle, you put
your life in danger,

and if you're thinking of
getting out of a stationary

one, then I guess the most
important thing is to pay

attention to the science and really be
aware of your surroundings.

[woman] You sit there.

[Dallas off-screen] And if
your friend puts you in a car

because you're a
bit worse for wear.

[woman] Yeah.

The greatest thing
I've ever, whoa!

Whoa!

[Dallas off-screen]
Stay in the car!

Some people never
listen to their friends.

[woman] Okay, come here.

Are you okay? Grab
her, grab her.

[woman] I'm sorry.

[woman] Whoa!

[Dallas off-screen] The woman
fails to place her foot on the

floor while rolling
her upper body out.

Once her center of mass
leans outside of her base of

support, gravity
makes her topple.

[woman] Oh my God!

I'm sorry.

[woman off-screen]
Okay, okay.

[Dallas off-screen] Looks
like she's fallen off the

wagon and out of it.

I always say there is nothing
more special than a husband

who cares for, and pays
attention to his wife.

This guy has clearly got this marriage
thing down to a fine art.

He might have to give
her an apology later,

maybe some flowers or even
a lesson in basic physics.

As his wife gets out of the
car, she turns her foot,

whilst her momentum
takes her forwards.

So her center of mass leans
outside of her base of support

and she quickly checks to see
if gravity is still working.

Which it is.

What a relief to see so many
people doing what should be so

simple with relative ease.

But there's always someone
who lets the side down.

As the bus begins
to pull away,

the man chooses to step out.

When his foot comes into
contact with the ground,

friction acts on
it, slowing it down,

whilst his momentum
keeps his body moving,

creating a turning force, and
a closer look at the curb.

Can you guess what key
scientific principle this

bench balancer is
about to show us?

[Dallas off-screen] We asked
you what science was being

demonstrated by
this park parkourist.

If you said muscle strength, give
yourself a pat on the back.

In order to adopt and
retain the handstand,

he needs to straighten his arms and
brace his mid-section.

But his elbows are flexed,
so he's relying on muscle

strength and is less stable,
meaning he can't control his

lower body and rotates,
all the way over.

In most mainstream
team sports,

athletes tend to
play with ba*ls.

But in ice hockey, they're not that way
inclined and prefer a puck.

But controlling one
is not that easy.

[Dallas off-screen]
See what I mean?

Perhaps building a training
session would help.

Eh, maybe not.

During an ice hockey game, a
puck can reach speeds of over



But before working on speed, it's
important to understand control.

[Dallas off-screen] The
hockey stick is an effective

class three lever so it can easily
impart velocity to the puck.

As soon as the
puck is airborne,

it becomes a projectile, follows a
curved parabolic trajectory.

When catching it, the player
needs to match the speed of

the falling puck so that
it decelerates more slowly.

This reduces the impact force
on the surface of the stick,

making it easier to control the
redirection of its velocity.

Now that we're armed
with a little science,

let's check how our
researchers are getting on

with their investigations.

[Dallas off-screen] Yep,
he seems to have got it;

but that looks ambitious.

[grunts]

Yeah, maybe a bit
too ambitious.

In order to achieve the
deceleration of the puck,

he starts with a
stick quite high,

but gets the angle wrong.

So rather than
slowing the puck down,

it ricochets and redirects
the velocity, quite painfully.

Once you've got the basics,
you can up the difficulty,

but try to stay on your feet.

This kid looks like he's got
his puck control down and

luckily he's set up a camera to record
his skills for posterity.

He launches the puck at the
wrong angle sending it on a

curved parabolic trajectory.

Smashing stuff.

Now it's time for today's
science lesson so thinking

caps on, engage those
brains and, Walker,

please stop making
those noises.

Right, who can tell me what
the following imprudent

individuals have in common?

[Dallas off-screen]
This junior genius.

[grunts]

This descending doofus.

And this car climbing klutz.

If you said
Newton's third law,

have yourself a gold star.

So, let's have a
look at an example.

And for a treat, we'll
be using a motorbike.

[Dallas off-screen] He starts
the bunny hop by opening the

throttle to generate torque
around the back wheel.

Newton's third law tells us
that this will induce an equal

and opposite reaction torque
that lifts the front of the

bike into a wheelie.

To hop, he pushes the
bike into the ground,

generating a reaction force
that propels him and the

bike into the air.

And when the bike lands, it
receives a reaction force from

the ground that is absorbed by
the suspension of the bike and

flexion of the riders
hips and knees.

Now the faster
you hit something,

the larger the force
you exert on it.

So the larger the reaction
force it exerts on you.

Right, question one: who
can tell me when reaction

forces are useful?

[Dallas off-screen]
The answer, of course,

is when you need to
overcome gravity.

As the brave boy
runs off the walkway,

the ground reaction
force disappears,

and he falls until the sand
exerts its own reaction force.

Going upstairs always
poses certain risks,

but this really ups the ante
and if you were to let go of

the stairs, the reaction force keeping
him aloft would disappear.

Just like that.

Question two: how are reaction
forces related to speed?

The answer is via
Newton's second law.

This states that the
faster you hit something,

the larger the force you exert
and the larger the reaction

force you feel.

[man] There is no way
that he just did that.

[Dallas off-screen] I
think it looks like he did.

[man] No.

No, no, no, no, no...

[Dallas off-screen]
Yes, yes, yes, yes, yes, yes.

Head butting bamboo
at high speed.

[man] Yah!

[Dallas off-screen] Will
also produce a large reaction

force, and a headache.

[man] Martin, did
that hurt mate?

Bamboo wins!

[Dallas] Time or our third and
final question: how can you

limit reaction
forces when you land?

[Dallas off-screen] You
could try landing on water.

But not like that.

Water is an unstable landing
surface because you get a much

smaller reaction force
from it than the ground.

But you do get some drag, so
his lower half decelerates,

his body position is thrown off and he
has a heavy landing.

So that's the end of our
lesson on Newton's third law.

Class dismissed.

[Dallas] Yesterday I saw my
doctor and she told me I was

having a mid-life crisis.

I was so shocked by the news I
nearly fell off my skateboard.

[Dallas off-screen] But it's not just
bad news from the doctor.

That will cause that.

Because skateboards
are not only tricky.

They are also very dangerous.

Skateboarding can be a risky
business if you don't know

what you're doing.

So, let's take a
look at the basics.

[Dallas off-screen] As he
rides back up the ramp gravity

decelerates him.

Once his velocity
reaches zero,

he performs a stall
with the board flat.

Fiction secures his
board onto the lip,

and to remain balanced, he
keeps his center of mass

forwards to stay in control as
he heads back down the ramp.

After that, a successful skateboard
stall should be straightforward.

So let's see how our
ever-ready researchers

are getting on.

[Dallas off-screen]
Has he got it?

No.

[man off-screen] [Bleep].

[Dallas off-screen] As he
attempts an axle stall on the

cage, the dog bites
his skateboard.

Down without a ride, the rider feels the
full force of gravity.

He seems pretty good for
a more mature fellow.

He's producing
some solid stalls;

all those years of
practice are paying off.

Or they were a
total waste of time.

As he attempts a stall
out of a half-pipe,

he doesn't make it
up onto the lip.

The skateboard easily rolls
away from him when he loses

his balance, and he
knocks his friend

over the fence.

Hopefully, this guy's got it.

[grunts]

I guess not.

[man] Ow!

[Dallas off-screen] While
he manages a basic stall,

as he travels back
down the ramp,

his center of mass
is too far back,

so his wheels accelerate
quickly out from under him

and gravity rotates him.

[grunts]

To the ground.

[man] Ow!

[Dallas off-screen]
Breathtaking stuff.

[man] I can't breathe.

[Dallas off-screen] Which
is pretty much what I said.

If children are
tiny scientists,

then play is the highest
form of research.

But if that's true then why do you see
so few of them in lab coats?

It might seem like
it's just for fun,

but play has a role and
development for both humans

and other animals.

[Dallas off-screen] Like this
horse who's playing with a ball.

Judging by that dive he could
be a successful soccer star.

And this playful p*ssy cat is
learning a valuable lesson

in life, and science.

Both physical and mental play can
improve cognitive abilities.

So next time someone
tells you to stop playing,

remind them that you're just
striving to better yourself.

[Dallas off-screen]
Functional play such as

chasing, develops the skill of
pursuit and capture that will

hold a real benefit when
individuals reach maturation

and need to fend
for themselves.

In some species physical play
can accelerate the development

of motor skills.

Social play is more subtle
through which infants develop

skills that are important for
adults, such as cooperation,

manipulation and trading.

Thus, increasing their chances
of success in later life.

Rats that are reared with lots
of playmates and toys tend to

develop larger brains
and learn more quickly.

So if you spot a rat next
time you're in the toy shop,

you'll understand why.

But they're not the
only ones having fun.

[Dallas off-screen]
Functional play like hunting

and ambush skills
take time to learn.

Adults like this big cat,
play a lot less than infants

because they've been through
the learning and development

stages already.

Next time pick on
someone your own size.

Toying with this tablet may
well set this corgi up for

a future career as
an app developer.

While his friend is going to
work in IT support.

The pooch's playtime could
develop mental and physical

skills that will serve them
both well in later life.

Playfully perusing the porch.

[man off-screen] Oh [bleep].

[Dallas off-screen] Has
taught him a valuable lesson.

Time spent in physical play
accelerates motor skill

acquisition in some species
and this puppy is getting a

schooling in friction,
grip and stability.

[man off-screen] Oh [bleep].

[Dallas off-screen] Remember,
sometimes no matter how much

you want to play, your playmate has
simply had enough.

Well, that's all we
have time for, for now,

and I hope you've been paying
close attention to the science

because you've seen what
can happen when you don't.

[music plays through credits].