the scientifically challenged and concentrate

科學挑戰者和集中

on one of science's heroes, Tyler Bradt,

科學界的英雄之一，泰勒-布拉德特。

kayaker extraordinaire.

皮划艇特級大師。

He wants to kayak over this, Palouse Falls in Washington.

他想在華盛頓的帕盧茲瀑布上劃皮艇。

Thousands of cubic feet of water pass over this fall

數千立方英尺的水從這個瀑布上流過。

every second and drop 186 feet to the pool below.

每秒鐘都會下降186英尺到下面的游泳池。

To consider kayaking over this, he must either

要考慮在這上面劃皮划艇，他必須要麼

be a few sandwiches short of a picnic,

還差幾個三明治就可以去野餐了。

or a world record breaker.

或打破世界紀錄的人。

We hope.

我們希望：

[music playing]

[音樂播放]

Oh.

哦。

There he is, the new world record

他在那裡，新的世界紀錄

holder of one of the most dangerous stunts

霸王硬上弓

I have ever seen.

我見過的。

Needless to say, even if you do have a 186-foot water feature,

不用說，就算你真的有186英尺的水景。

don't try this at home or anywhere else.

不要在家裡或其他地方嘗試這個。

Falling off a waterfall is the easy part.

從瀑布上掉下來是很容易的事。

But as gravity initially accelerates you down

但是，由於重力最初加速了你的下降

at 32 feet per second per second,

以每秒32英尺的速度。

it's surviving that's the tricky bit.

它的生存，是棘手的位。

Our kayaker must go over the falls at the correct speed

我們的皮划艇必須以正確的速度越過瀑布。

to give gravity just enough time to generate

給予引力足夠的時間來產生

the angular velocity needed to rotate the kayak 90 degrees.

將皮艇旋轉90度所需的角速度。

This angle minimizes hydrodynamic drag,

這個角度可以使流體動力阻力最小化。

so he experiences less impact force

所以他受到的衝擊力較小

and cuts through the water.

並切開水面。

It's also worth noting that a kayak's stability is

值得注意的是，皮划艇的穩定性在於

dependent on keeping the center of mass

依賴於保持品質中心

in line with the center of buoyancy,

與浮力中心一致。

which is in the middle of a submerged volume.

處於淹沒的體積之中。

Otherwise.

不然的話

OK.

好的

Science-taught, let's see if our team of want-to-be record

理科出身的我們看看我們的團隊是否想創下

breakers have learned.

斷者已經瞭解到。

He's practicing the science with a man-made kind of waterfall,

他在用一種人造的瀑布來實踐科學。

but the law of gravity is the same.

但萬有引力定律是一樣的。

The thin layer of water acting as a lubricant

作為潤滑劑的薄層水

combined with the steep angle allows gravity to do its thing.

再加上陡峭的角度，讓重力發揮其作用。

It's not quite the 32 feet per second

還沒有達到每秒32英尺的速度。

per second of a waterfall freefall,

每秒鐘的瀑布自由落體。

but he's only practicing.

但他只是在練習。

On to angular velocity, or in this case, the lack of it.

說到角速度，或者在這種情況下，沒有角速度。

Launching too fast meant he gained very little angular

發射速度太快，意味著他獲得的角度非常小。

velocity, hitting H2O at a terrible angle,

速度，以可怕的角度撞擊H2O。

thereby maximizing hydrodynamic drag.

從而最大限度地提高流體動力阻力。

Which is bad, as it brought him to an almost immediate and very

這是不好的，因為這給他帶來了一個幾乎是直接的，非常的

painful stop.

痛苦的停止。

Waterfall.

瀑布。

Check.

檢查。

Angular velocity.

角速度。

Check.

檢查。

Stability.

穩定性；

Check, ish.

檢查，是的。

It's an upside down check, but technically he still got

這是一個顛倒的檢查，但技術上他仍然得到了。

himself into a stable position.

自己進入了一個穩定的位置。

It's just a shame his center of mass

只可惜他的品質中心位置

is directly below his center of buoyancy,

是在他浮力中心的正下方。

as his head is the thing he uses to breathe.

因為他的頭是他用來呼吸的東西。

Cheering without acknowledging the person

歡呼，卻不承認這個人

that just saved your life.

這只是救了你的命。

Check.

檢查。

Even if our want-to-be record breakers do get to grips

即使我們想打破紀錄的人也能掌握住。

with angular velocity, hydrodynamic drag,

與角速度、流體動力阻力。

and stability, like Tyler did, 186 feet is just too dangerous.

和穩定性，就像泰勒那樣，186英尺實在是太危險了。

Maybe it's better to kayak somewhere safer, like a puddle.

也許在安全的地方劃皮艇比較好，比如水坑。