Kind: captions
Language: en
[Music]
If I uh apply a force to the globe, I
can actually get it spinning
in roughly the same way that the Earth
spins. But it is it is tricky. There's
very little friction on the bottom
because of it being supported on this
thin layer of water. And you can see the
more force I apply to it, the more it
accelerates.
Oo. So, we're getting it speeding up
here.
When you when you push that, like it's
not too easy to to get it going. Why is
that?
Friction. Probably
so strangy.
Why is it not really easy to push? What
is it about this giant spear that makes
it a challenge to push?
The weight.
The resistance.
Gravity. Gravity.
It's really heavy, too. So, I'm pretty
sure the weight of it sitting down is
making it tough, too.
You don't think its weight is supported
by that water?
Well, I know it's supported, but even
though it's supported down, moving it,
it's still like if it center of gravity
is here, we still have to push the
weight coming out from here. So, it's
pretty heavy. I'm pretty sure.
Most people will say if you just apply a
force to it, it starts moving.
That's not really the point I want to
make. The point I want to make is the
more force you apply to it, the more it
speeds up, more gets going faster and
faster and faster. But it's got 2 and 12
tons of inertia. So you can really feel
that you have to push hard to accelerate
it. What do you feel when you push on
it?
Just moves. When you push something, it
moves.
Does it do something more than move?
Spinning. It's rotation, velocity,
speed. There's some word you're looking
for.
There is a word I'm looking for. What do
you feel? Is that hard?
Uh, not really.
It's easy. It's not going very fast,
though.
It's not like hard to push, but it's
sort of hard to get going fast.
It's too big to make it fast.
Is it hard to make it fast?
Yeah.
Why is it hard to make it fast? Can we
try?
Yeah.
Let's try it. Let's get it going really
fast. Yeah.
How is that?
Rotating. Spinning.
So close.
Moving.
How do you make it go faster?
Um, you only need to push hard hard and
more harder than that.
You put a force on an object, a net
force, an unbalanced force, and it
it
come on goes.
the least scientific. Whatever. It goes.
You study physics, right?
Yeah. Which means I'm probably looking a
little bit like a here at all.
It's easy to push, but like if you try
to go fast, then it just sort of stays
the same speed.
But could you bring it to a stop?
Probably not. Definitely not.
Can you give it a shot?
Stop the water.
Well, other than cheating. Yeah.
What do you think? Not going to happen.
Really? Come on. Come on. Come on. Put
your back into it. You can do it.
I don't think it's going to work, but we
can give it a shot.
Kind of.
What do you see there?
It's stopped, but I It's only stopped
cuz it's on like a very soft thing of
water pretty much. I'm pretty sure.
So, do you It's not going to stay
stopped or what? It shouldn't.
[Music]
Huh. All right.
Are you applying a force to this uh
sphere here?
Yes.
What happens when you apply a force to
the sphere?
Then it changes like speed.
That's a pretty awesome observation
you've just made.
Yeah.
Do you know that?
I guess.
So, we could generalize. We could say
force causes
change speed.
Man, you are nailing this. Can you give
me a high five? Boom.
What do you think physics is?
Um, like how things work, I guess.
And you want to know how things work?
Yeah.
How old are you?
11.
You seem pretty smart for being 11.
Okay.
Do people tell you that you're smart?
No.
Do you think you're smart?
No.
I think you're smart.
Okay.
You take my word for it.
Okay.
Really?