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Did you know that a 10 meter platform diver covers the last seven meters they fall in less time than the first three?
你知道吗 10米跳台运动员最后7米所用的时间比前3米还要短
Actually, this also applies to a falling rock… but rocks aren't nearly as good looking.
实际上这个规律对石头也管用 尽管石头样子寒碜了点
Anyway, by the time a diver (or rock) has fallen three meters, they're already going about 17mph,
不论如何 跳水运动员或石头下落3米时 速度将达到每小时17英里(27.6km/h)
and as they fall farther, they continue to pick up speed so that they cover the remaining distance in less time.
并且他们的速度会随着下落的距离继续增加 因此会用更短的时间完成剩下的距离
But now suppose a world record sprinter races our olympic diver -
现在我们假设短跑冠军和奥运跳水运动员比赛
that is, Usain Bolt starts ten meters from the finish line,
即博尔特在终点线前10米起跑
and the diver starts ten meters above it.
跳水运动员在终点线前10米起跳
Who gets there first?
谁会赢
Well, Bolt's actual running time through the first 10 meters of his world record was 1.74 seconds,
根据世界记录 博尔特跑完前10米用了1.74秒
while a rock falling 10 meters takes only 1.43 seconds…
但石头落10米只要1.43秒
so victory to the rock by a slim margin.
所以石头以微弱的优势胜利
But of course, an olympic diver is NOT a rock,
但是 跳水运动员不是石头
and in particular they'll jump upwards off the platform
而且他们要在跳板上向上起跳
- this means they'll be in the air for an additional third of a second,
这意味着他们将会多用三分之一秒
or a total of about 1.78 seconds before they hit the water.
因此他们在入水前总共用去1.78秒
So it's actually a close race, and Bolt wins the photo finish!
所以这是场势均力敌的比赛 博尔特以微弱优势获胜
However, while we continue to be amazed by how fast Usain Bolt is, the fact that he could beat a diver in free fall is more of a reminder that
但是在我们感叹博尔特神速之余 我们更应该从中得到一个启示
while gravity a law of nature and thus consistent, doesn't give you a blazing start.
重力作为自然界的基本机制 也许一开始并不会让你感到惊讶
That's why it's easiest to catch something in the first instant after you drop it.
但它解释了为什么我们很容易接住刚刚开始下落的物体
If you wait even a second, it'll be 15 feet down and already traveling 20 miles per hour.
而迟疑了哪怕1秒钟 它已经以20英里每小时(35km/h)的速度奔到15英尺(4.9米)开外了
Bye bye!
再见!
