Do you have a friend or a sibling that's always competing with you to see who's the fastest?
你是否有一个朋友或者姐妹，总是跟你竞争看谁最快吗？
Our alien friends Bleebop and Mark are having the same debate with their custom-built rockets,
我们的外星朋友Bleebop和Mark正在关于他们定制的火箭进行同样的辩论，
and they've asked us to be the judge of a space race to their moon.
并且他们要我们来当这场“去月球太空速度竞赛”的裁判。
The only problem is that they are starting from different asteroids.
唯一的问题是，他们是从不同的小行星开始的。
Bleebop is on an asteroid 240 miles from the moon, and Mark is on one 150 miles away.
Bleebop在一个离月球240英里行星上，而Mark则是在一个离月球150英里的行星上。
Don't worry, it's not rocket science.
不用担心，这不是火箭科学。
Solving this equation is as simple as DIRT.
解出这个等式就和DIRT一样简单。
We can decide who the winner is using the D=RT formula, or DIRT.
我们可以通过使用D＝RT的公式，或者“DIRT”，决定谁是赢家。
This stands for distance equals rate times time.
这个公式代表“距离=速率x时间”。
In the case of Bleebop and Mark, we will only know the distance they traveled
在Bleebop和Mark的这件事中，我们只需知道他们所经过的距离
and the time it took for them to get to the finish line.
和他们用来到达终点的时间。
It'll be up to us to find the rate and who is faster.
便可得出它们的速度和谁是更快的那一方。
Let's turn to the race now and see what information we get. Three, two, one, blast off!
让我们现在来关注这一竞赛，并且来看看我们所能得到的信息。三，二，一，发射升空！
Bleebop and Mark's rockets go zipping across the galaxy towards their moon,
Bleebop和Mark的火箭飞快地穿过银河，并向月球飞去，
dodging clunky meteorites and loopy space buggies.
他们躲闪过了沉重的陨星和呆头呆脑的太空老爷车。
After a few close calls with a wandering satellite,
在差点与一些漫游卫星碰撞而死里逃生之后，
Mark arrives first in two hours, and Bleebop gets there one hour later.
Mark在两小时后率先到达，而Bleebop则在他一小时后到达了。
Looks like Mark has the faster rocket, but let's check out the results with our DIRT equation.
看上去好像Mark有一个更快的火箭，但是让我们再用DIRT等式检查一下结果。
Begin by setting up a chart. Make four columns and three rows.
首先，新建一张表，做成四列三排的样子。
Use DIRT to remember what to fill in.
用DIRT公式来记录填进去的内容。
Each rocket will have information for distance, rate, and time.
每个火箭都会有关于距离、速率和时间的信息。

Mark's rocket went 150 miles, we don't know the rate, and he got there in 2 hours.
Mark的火箭走了150英里，我们不知道速率，只知道他花了2个小时。
Bleebop's rocket went 240 miles, we don't know the rate, and the time is 1 hour after Mark, or 3 hours.
Bleebop的火箭走了240英里，我们不知道速率，只知道他要比Mark晚了一小时到达，也就是总共用了3个小时。
Because we don't know Mark or Bleebop's rate,
因为我们不知道Mark或者Bleebop的速率，
that number is going to be a variable in each equation, which we'll represent with x.
所以这个数字将会成为每个方程式里的变量，我们可以用X表示。
We'll solve the equation for the variable to find its value.
我们会解方程并求出变量的值。
Mark finished first, so start with his rocket.
Mark先到达，所以从他的火箭开始。
Remembering DIRT, write down D=RT.
记住DIRT公式，写下D＝RT。
150 miles equals x times 2 hours. Divide both sides by 2 hours.
150=2X。两边同除2。
This will leave x isolated on the right side of the equation.
使X成为在等号右边唯一的量。
150 miles divided by 2 hours is 75 miles over 1 hour.
150英里除以2个小时是75英里每小时。
Mark's rate is 75 miles per hour. That's what mph means.
Mark的速率是75英里每小时。也就是mph的意思。
It's the amount of miles over one hour. Still think Mark is faster?
它是在一个小时内的英里总数。你还认为Mark更快吗？
Let's set up the same equation for Bleebop and see.
让我们来给Bleebop设定同一个方程，再来看看。
D=RT, 240 miles equals x times 3 hours. Divide both sides by 3 hours.
D=RT，240=3X，两边同时除以3个小时。
This will leave x isolated on the right side of the equation.
使X成为在方程的右边唯一的量。
240 miles divided by 3 hours is 80 miles over 1 hour.
240英里除以3个小时是一个小时80英里。
Bleebop's rate is 80 miles per hour.
Bleebop的速率是80英里每小时。
Wow, even though Bleebop got there one hour later, it turns out he had the faster rocket.
哇，尽管Bleebop晚了一个小时到达，但其实他有着更快的火箭。
Mark seems pretty upset, but with aliens, you can never really tell.
Mark看上去很沮丧，但关于外星人的一些事，我们谁也说不准。
Thanks to DIRT, you now know how to calculate distance, rate, and time.
多亏了DIRT公式，你现在知道怎么去计算距离，速率还有时间了。
In what other situations can you use the distance formula?
在其它什么情况下你也可以使用距离公式呢？
You don't even need to be watching a space race.
你甚至不用去看太空竞赛。
As long as you know two pieces of information for the formula D=RT, you can calculate any moving vehicle or object.
只要你知道公式D＝RT中的两部分信息，你就能计算出任何关于车辆或者物体移动的信息。
Now, the next time you're in a car, you can let your friends know exactly when you'll be arriving,
下次当你在一辆轿车上时，你便能让你的朋友知道你将会到达的准确时间，
how fast you're going, or the distance you'll travel. It's as simple as DIRT.
你的速度或者你需要经过的路程距离了。这和DIRT一样简单。