未登录,请登录后再发表信息
最新评论 (0)
播放视频

伽利略定理的解释装置

Physics marble track review part one // Homemade Science with Bruce Yeany

[music]
[音乐]
Homemade Science with Bruce Yeany
布鲁斯耶尼的家庭科学课
Hello, I’m Bruce Yeany.
大家好 我是布鲁斯耶尼
Today in Homemade Science I’d like to take a look at
今天的家庭科学课上 我们来看看
some of my marble tracks that I’ve built over the years.
我这些年建造的弹珠轨道
Now I build these pieces as a way of introducing
现在 我们看到的这些装置用来介绍
or reinforcing students’ ideas on motion and acceleration,
介绍或强化大家对运动和加速度
inertia, potential and kinetic energy.
惯性 势能和动能的认知
So let’s take a quick look at some of them.
接下来我们看看这些装置
This piece I refer to as a Galileo track,
这一段我称为伽利略轨道
it starts at the same height on either side,
小球从两边相同的高度开始下落
but this side is three times longer than this side is.
但是这一边的长度比另一边长三倍
And so my first question would be,
所以我的第一个问题是
if I were to release the ball here,
如果我把球放在这里
could it possibly roll off the opposite side?
它有可能从另一边滚出去吗?
Let’s give that a quick try.
我们来试试看
And we see it doesn’t.
我们看到它没有
How about if I try it from this side?
如果我从这边来呢?
and it won’t do it from that side either.
它也不会从那边滚出去
This piece was important because it was actually
这个装置很重要 因为它实际上
a piece that Galileo designed to help explain the idea of inertia.
是伽利略做出来帮助理解惯性的装置
When looking at probabilities,
当我们考虑可能性的时候
here are two examples of prediction tracks.
这里有两个关于轨迹预测的例子
For example, will I get a million views for this video?
例如 本视频的浏览量会达到一百万吗?
Here’re my choices.
这儿是我的选择
I’d say yes,
我会说是的
it’s possible,
这是可能的
chances are slim,
机会很小
and no way.
不可能
Well I was hoping for better,
我希望结果会更好
but it looks like my chances are very slim.
但看起来我的机会很渺茫
Now this piece has two tracks that have identical curves.
这个装置有两个曲线相同的轨道
And as you can see on the side it says,
你可以从标注上看到
“Which position gets the ball to the bottom the quickest?”
哪个位置能让球最快到达底部?
So for this piece,
对于这个装置
if we lift the balls to the same position to release them,
如果我们把球举到相同的高度并释放它们
we would expect them to get down to the bottom together.
我们可能会希望它们同时滚到底部
But what would happen if we put them at different positions?
但若把它们放在不同的位置 会发生什么呢?
We find that position doesn’t make a difference.
我们发现和之前没什么区别
If we release them at the same time,
如果我们同时释放它们
they will reach the bottom together.
它们就会一起到达到底部
Now I built this piece to help explain the behavior of pendulums
我做出这个装置是为了帮助解释钟摆的行为
in regards to a revelation that was made by Galileo.
其与伽利略发现的定律有关
Now here we have two pendulums that have the same length,
现在我们有两个长度相同的钟摆
and if I pull them back the same distance,
如果把它们拉到相同的位置
well, they swing together, they have the same period.
让它们一起摆动 它们有相同的周期
It takes the same amount of time for it to
来回移动一次
move back and forth for one movement.
它们用时相同
But Galileo showed that if I pulled them back different distances,
但是伽利略发现 如果把它们拉到不同的距离
they still had the same period,
它们仍然有相同的周期
with the same amount of time for it to swing back and forth for one movement.
来回摆动一次需要相同的时间
Now if I pull the apples back and release them at different times,
现在 如果我把苹果拉回来 在不同时间释放
we can hear them hit at different times.
我们可以听到它们在不同时间撞击的声音
If I pull them back together to the same distance and release them together,
如果我把它们拉回相同的距离 然后一起释放
they hit together.
它们会同一时间撞击
Now let’s try pulling them back different distances,
现在我们试着将它们拉到不同的距离
but releasing them at the same time,
但同时释放它们
once again we hear that they’re hitting together.
我们再次听到它们同时撞击的声音
The same is what we find on this track.
我们在这条轨道上也发现了同样的情况
Now I think one of my favorite pieces have been the high-low tracks.
这个是我最喜欢的装置之一——高低轨道
I have a number of them,
我建造了很多高低轨道
and they start out very simple.
我们从简单的开始
Something like this,
像这个
and as you can see there’s two tracks,
你可以看到这儿有两条轨道
both tracks start at the same height,
两条轨道从同一高度开始
and end at the same height.
在同一高度结束
But their path from one side to the other is completely different.
但它们从一边到另一边的路径完全不同
This one is a straight path,
这条是笔直的通道
that’s the shortest distance between two points,
这是两点之间最短的距离
whereas this track drops down to a lower level,
而这条轨道向下延伸到一个较低的位置
covers a lot of distance and then
然后跨越了很长的距离
finally comes back up again at the very end.
最后也抵达了终点
So the question is,
接下来我们的问题是
which track would get a ball over to the opposite side the quickest?
哪条轨道能让球最快抵达对面
Well, I have two steel balls here,
我这里有两个钢球
let’s give it a try.
我们试试看
This track drops quite a bit lower but we still see the same results.
这条轨道更陡 但我们仍然看到相同的结果
Same idea, only this time I’ve added a hump in the center right here,
同样的想法 只是这次我在中间加了一个坡
let’s see what happens with this one.
我们来看看加了这个坡会发生什么
We have a track that has two humps.
我还有一条有两个坡的轨道
This track I use to help explain the behavior of pendulums.
这是我用来解释钟摆摇摆轨迹的装置
The tracks are the same length,
轨道的长度是一样的
but as you can see the slope is much different from one to the next.
但正如你所看到的 从一个到下一个坡度的大小是不同的
The first track represents a pendulum that is 24cm long,
第一个轨道代表24厘米的钟摆
and it would have a period of 1 second.
周期为1秒
This track back here represents a pendulum that would be 99cm long,
后面这条轨道代表长99厘米的钟摆
and it would have a period of 2 seconds.
它的周期为2秒
And the third track back here which is much gentler,
这里的第三条轨道要慢的多
represents a pendulum that is 222cm long,
它代表长222厘米
and it would have a period of 3 seconds.
周期为三秒的钟摆
So this helps to visualize why longer pendulums have a longer period.
这有助于理解为什么更长的钟摆有更长的周期
Now if you want information on any of these pieces,
现在 如果你想知道更多这些装置的信息
I’ve made videos on all of them,
我已经拍了所有装置的视频
and you can find a listing of them in the comment section below.
你可以在下面的评论部分找到它们
As always I’d like to thank you for watching,
非常感谢大家的观看
and go on to part two, I’ll show you some construction tips
下期视频我将给大家展示一些
on how to build your own tracks
搭建自己轨道的技巧
and I’ll end up building a loop-de-loop track.
我还将会建立一个环路
OK, bye!
好的 再见

发表评论

译制信息
视频概述

这是一个解释伽利略发现的定理的装置。它由三部分组成:高低轨道、钟摆装置、解释伽利略定理的小球实验。

听录译者

Alef

翻译译者

算了

审核员

审核员 V

视频来源

https://www.youtube.com/watch?v=JWtsOiVxIIE

相关推荐