that's always competing with you

一個總是和你競爭

to see who's the fastest?

和你比誰比較快的人？

Our alien friends Bleebop and Mark

我們的外星朋友，Bleebop和Mark

are having the same debate

正為了相似的情況爭執

with their custom-built rockets,

他們比的是他們各自定制的火箭

and they've asked us

他們請我們當裁判

to be the judge of a space race to their moon.

裁定誰能在比賽中最快到達他們的月球

The only problem is that they are starting

但有個問題是

from different asteroids.

他們是分別從不同的行星出發的

Bleebop is on an asteroid 240 miles from the moon,

Bleebop從距離月球240英里(386.23公里)的行星出發

and Mark is on one 150 miles away.

Mark則從距離月球150英里(241.40公里)的行星出發

Don't worry, it's not rocket science.

別擔心，這不是困難的火箭精密科學

Solving this equation is as simple as DIRT.

只要運用DIRT公式就能解出這個方程式

We can decide who the winner is

我們可以輕易的找出贏家

using the D=RT formula, or DIRT.

用D=RT這個公式，或稱DIRT公式

This stands for distance equals rate times time.

意思是距離(D)等於速率(R)乘以時間(T)

In the case of Bleebop and Mark,

在Bleebop和Mark的比賽中

we will only know the distance they traveled

我們只知道他們的火箭航行了多遠的距離

and the time it took for them

和他們花了多久的時間航行

to get to the finish line.

才到達終點線

It'll be up to us to find the rate

我們得找出他們航行的速率

and who is faster.

和誰的火箭比較快

Let's turn to the race now

現在讓我們來看看比賽吧

and see what information we get.

看我們能從比賽中發現什麼

Three,

三

two,

二

one,

一

blast off!

發射！

Bleebop and Mark's rockets go zipping

Bleebop和Mark的火箭飛向太空

across the galaxy towards their moon,

脫離行星的重力，航向他們的月球

dodging clunky meteorites

躲開巨大的隕石

and loopy space buggies.

和迷路的太空越野車

After a few close calls with a wandering satellite,

驚險的避開幾顆脫軌的衛星後

Mark arrives first in two hours,

Mark花了兩小時的航程率先到達

and Bleebop gets there one hour later.

一小時後，Bleebop也到達終點了

Looks like Mark has the faster rocket,

看上去Mark的火箭跑得比較快

but let's check out the results with our DIRT equation.

但讓我們套DIRT公式來看看

Begin by setting up a chart.

先畫一個圖表

Make four columns and three rows.

畫一個四列三欄的圖表

Use DIRT to remember what to fill in.

代入DIRT公式 來記憶每一格要填上什麼

Each rocket will have information

兩人的火箭分別有這些資訊：

for distance, rate, and time.

距離、速率和航行時間

Mark's rocket went 150 miles,

Mark的火箭航行了150英里(241.40公里)

we don't know the rate,

我們不知道速率

and he got there in 2 hours.

他花的航行時間為兩小時

Bleebop's rocket went 240 miles,

Bleebop的火箭航行了240英里(386.23公里)

we don't know the rate,

我們不知道速率

and the time is 1 hour after Mark,

他比Mark多花了一個小時到達

or 3 hours.

或說花了三小時

Because we don't know Mark or Bleebop's rate,

因為我們不知道Mark和Bleebop的火箭航行速率

that number is going to be a variable

這個數字就會是個變量

in each equation,

在這兩道公式裡

which we'll represent with x.

我們都以X來代表這個變量

We'll solve the equation

我們解開這個公式

for the variable to find its value.

以找出這個變量的正確數值

Mark finished first,

Mark先到達終點

so start with his rocket.

所以我們從他的火箭開始分析

Remembering DIRT, write down D=RT.

想著DIRT公式，寫下D=RT

150 miles equals x times 2 hours.

150英里等於"變量X"乘以"兩小時"

Divide both sides by 2 hours.

將等式雙方各除以兩小時

This will leave x isolated

等式右方

on the right side of the equation.

就會單獨留下變量X的值

150 miles divided by 2 hours

將150英里除以兩小時

is 75 miles over 1 hour.

即為75英里一小時

Mark's rate is 75 miles per hour.

Mark的速率為一小時75英里

That's what mph means.

速率的簡寫"MPH" 代表"小時英里(Miles per hour)"

It's the amount of miles over one hour.

即一小時中總共航行的距離

Still think Mark is faster?

還覺得Mark的火箭飛得比較快嗎？

Let's set up the same equation for Bleebop and see.

我們將Bleebop的航行也代入公式裡分析看看

D=RT

距離等於速率乘以時間(D=RT)

240 miles equals x times 3 hours.

240英里等於"變量X"乘以"三小時"

Divide both sides by 3 hours.

將等式雙方各除以三小時

This will leave x isolated

等式右方

on the right side of the equation.

就會單獨留下變量X的值

240 miles divided by 3 hours

將240英里除以三小時

is 80 miles over 1 hour.

即為80英里一小時

Bleebop's rate is 80 miles per hour.

Bleebop的航行速率為一小時80英里

Wow, even though Bleebop got there one hour later,

哇，雖然Bleebop晚了一小時才到達終點

it turns out he had the faster rocket.

計算結果反而是他的火箭飛得比較快

Mark seems pretty upset,

Mark看上去頗為沮喪

but with aliens, you can never really tell.

但在外星人身上 你很難判讀他的真正心情是什麼

Thanks to DIRT, you now know how to calculate

感謝DIRT公式

distance,

現在你知道怎麼計算距離

rate,

速率

and time.

和時間了

In what other situations

在其他情況下

can you use the distance formula?

你能應用上這個距離公式嗎？

You don't even need to be watching a space race.

其實你處處能用上它 不單只在看太空競賽的時候

As long as you know two pieces of information

任何情況下 只要你知道公式中的兩項資訊

for the formula D=RT,

距離等於時間乘以速率中的兩項數值

you can calculate any moving vehicle or object.

你就能將它應用在 所有移動中的物體或交通工具上

Now, the next time you're in a car,

當下次你坐車的時候

you can let your friends know

你可以以精確的數字告訴你的同行朋友

exactly when you'll be arriving,

你們會花幾個小時到達目的地

how fast you're going,

你們現在移動得多快

or the distance you'll travel.

或你們移動了多遠的距離

It's as simple as DIRT.

只要用上DIRT，就是非常簡單的事！ －Translated by Peggy Tsai