Name: Intro to vectors & scalars | One-dimensional motion | Physics | Khan Academy
Uploaded: 2016-10-18T08:15:51.000Z
Duration: 8 min 39 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

To-infinitive

The imperative

talk about the difference between vectors and scalars.

And they might sound like very complicated ideas,

but we'll see over the course of the videos

So first I'll give you a little bit of a definition.

And then I'll give you a bunch of examples,

and I think the examples will make things super clear.

Hopefully, they'll make things super clear.

A vector is something that has a magnitude,

or you could kind of view that as a size,

Let's say that I have, let's say that that's

the ground-- let me do the ground in a more

And I pick up that brick, and I move it over

And then I take a ruler out, and I say, wow,

So my question to you, is my measurement of 5 meters,

You just know the magnitude of the movement.

And when we're referring to moving something,

or how much something has, I guess, changed its position,

And I'm assuming you've heard the word distance.

How far of a distance has something traveled?

So we could say that this block, or this brick,

because of my picking it up and moving it,

But if I didn't show you this picture here,

wouldn't know if it moved to the right 5 meters,

you wouldn't know if it moved to the left 5 meters,

or-- You don't know what direction it moved 5 meters.

could say that this brick right over here,

Now we have specified a magnitude, right over there.

And we have specified a direction, to the left.

So you now explicitly know that they went 5 meters to the-- oh,

So, 5 meters to the right is what it got moved.

It started here and went 5 meters to the right.

So once again, the magnitude is 5 meters,

So what I've just described to you right here

So this, all of this business right over here,

And when you talk about the movement, the change

in position, and you give its direction, the vector version

of distance, I guess you could call it, is displacement.

Distance is a scalar quantity-- I didn't tell you

Now let's explore this if we talk about the actual,

well, we'll talk about the speed or velocity of something.

So let's say that this 5 meters was traveled

So let's say that the change in time right here,

let's say that the change in time was 2 seconds.

So maybe right when the block started moving, maybe

And then on my stopwatch when it stopped moving,

it said, or when it got to this position,

I should say-- when it left from this position,

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Intro to vectors & scalars | One-dimensional motion | Physics | Khan Academy

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