Name: 1-1（Triboelectric effect and charge | Physics | Khan Academy）
Uploaded: 2022-07-19T03:00:43.000Z
Duration: 11 min 45 s
Description: 【看影片學英語】數萬部 YouTube 影片，搭配英漢字典即點即查，輕鬆掌握單字發音與用法，長久累積看電影不必再看字幕。

- I'm guessing that you've had the experience of rubbing

a balloon against your hair and then when you take

the balloon away from your hair, your hair sticks up.

but I'm guessing most of you all have done that.

And you had a sense that it had something to do with the

balloon or your hair, somehow exchanging charge or now

one is going to be more positive or negative than the other,

And if you were thinking of those things,

What you just experienced after you rubbed the balloon

on your head, and then your hair is now attracted

the triboelectric effect, let me write that down,

And human beings have been observing this

for a long long time, and it wasn't necessarily

with balloons at birthday parties or whatever,

it's with other things, they rub a silk cloth on a piece

of glass and then they'll see that there's some type

of attraction, or they might see that if they

do that enough, one of the objects might discharge

People have observed things like lightning,

where it looks like there's some type of a buildup

and some type of a potential and then all of a sudden

it discharges and you have this lightning and then this

So this is something that humans have observed

for a long long time, and scientists or people with a,

I guess you could say a scientific mind have been trying

to understand it for a long long time, and trying to come up

with a framework for what exactly is happening.

Well lucky for us, we now have a framework for it

Is a framework that we now have around charge.

And this tells us, this way of looking at the world,

Some things have a positive charge, and it's somewhat

of an arbitrary name, we just happen to call it positive.

And some things have what we say is an opposite charge,

We could have called this the magenta charge,

and this the green charge, we could have called this

the hippopotamus charge and this the ostrich charge.

And we could have said that hippopotami, I believe plural

for hippopotamus, they're always attracted to ostriches,

but they always repel other hippopotami, and likewise.

But I'll stick to the words that people are used to using.

and something else has a negative charge,

then in our framework that we're setting up,

So opposite charges are going to attract,

are going to accelerate away from each other.

And that's not just true for positive positive,

that's also true for negative and negative,

Now it's very interesting to think about this

because we are so used to thinking in terms of charge,

even you know if, especially in kind of the world

of electricity you have the positive and negative terminal.

You think of charging up your phone or whatever else.

That it seems like, we completely, charge is just something

but you'd have to appreciate that these are arbitrary words

and they're really just to describe a property

And if you go down to the atomic level, we can get to

a fundamental level of where the charge is happening.

for our brain to describe, these are frameworks and models

for our brain to be able to predict and describe

the nuclei of atoms are composed of protons and neutrons.

So if you have some protons, and then you have

some neutrons, I'll do two of each, you have some neutrons,

and based on this framework, protons have a positive charge.

Now once again, this convention of calling them positive

and putting a plus on it, it's not like protons have

字幕列表影片播放

1-1（Triboelectric effect and charge | Physics | Khan Academy）

grab

matter

scale

experience