在线英语听力室

时差N小时 为什么定位空中的飞机如此难?

时间：2021-08-26 09:58:19

搜索关注在线英语听力室公众号：tingroom，领取免费英语资料大礼包。

（单词翻译）

How many times have you heard a jet plane going over, looked up to see it, but not been able tofind it even though you were looking toward where the sound was coming from?

有多少次你听到一架喷气式飞机飞过，抬起头去看它，即使你朝着声音传来的地方望去，却仍然无法找到它？

Well, thismoment of science is going to tell you why you couldn't find it?

那么这次科学时刻将会告诉你为什么你找不到它。

Sometime during your life you might have been told that the plane wasn't with the sound becauseit was traveling faster than the speed of sound.

在你生活中的某个时候，你可能被告知看到的飞机和听到的声音是不在同时出现的，这是因为光的传播速度比声音快。

It might have been, but it didn't have to be goingthat fast in order to appear to be separated from the sound.

它可能是这样的，但它没有必要为了同声音分离而飞的那么快。

The reason the jet appeared to be apart from the noise it was making was simply that soundtravels a lot more slowly than light-about a million times more slowly.

喷气式飞机之所以和它产生的噪音相分离，是因为声音传播速度比光速慢一百万倍。

For quick review, at sea levelsound travels about seven-hundred-fifty miles per hour, light travels at 186,000 miles per second.

简单回顾一下，在海平面上，声音的传播速度大约是每小时750英里，而光速则是每秒186，000英里。

Commercial jets normally fly at about thirty-thousand feet.

商用喷气式飞机一般在30，000英尺的高空飞行。

From that height it takes sound aboutthirty seconds to reach earth.

从那个高度，声音传送到地面需要30秒的时间，

Light gets here in only about four one-hundred-thousandths of asecond, or for practical purposes, instantaneously.

而光到达地面仅仅需要4/100，000秒，实际上就是瞬间到达。

A plane travelling at six-hundred miles an hour goes five miles in the thirty seconds it takes for thesound to reach you.

一架每小时飞行600英里的飞机在30秒中飞行了5英里，而声音传到你所在的地方需要30秒。

By the time the sound from the plane reaches your ears, the plane is fivemiles from where that sound originated.

在这30秒的时间里，声音从飞机传到你的耳朵里，而飞机离声音发出的地方已经有了5英里的距离。

So, when you look toward the sound, the plane is notthere anymore.

所以，当你朝声音发出的地方望去的时候，飞机早已不在那里了。


分享到：


点击收听单词发音收听单词发音  

0 able 2ISy5     
adj.能...的，有才能的，能干的，能够的
参考例句：
  • How good and able he is!瞧他多能干啊！
  • He is able to do this job well.他有能力做好这件工作。
0 anymore 2z9zUD     
adv.不再， 再也不
参考例句：
  • She doesn't live here anymore.她已不在这里住了。
  • He doesn't come here anymore.他再也不到这儿来。
0 apart uM2y1     
adv.除去，撇开；分开；相隔，相距
参考例句：
  • I helped her pull the two fighting boys apart.我帮她把两个打架的男孩拉开。
  • I like to keep my work apart from my family.我不喜欢让家里人插手我的工作。
0 appear fvnzw     
vi.出现，出场，出席，露面；似乎，好像，显得
参考例句：
  • The students appear very nervous.学生们看起来很紧张。
  • When night falls,stars appear.夜晚来到时星星出现。
0 appeared appeared     
v.出现( appear的过去式和过去分词 )；出庭（作证或受审）；演出；发表
参考例句：
  • Her beauty appeared ageless. 她的美显得经久不衰。
  • He appeared at breakfast bleary-eyed and with a hangover. 他吃早餐时两眼迷糊，宿醉未醒。
0 commercial 6OZz8     
adj.商业的，商用的，商品化的；n.广告节目
参考例句：
  • He has gained a footing in the commercial world.他已在商界取得立足之地。
  • The plane did not fly the usual commercial route.飞机没有沿通常的商业航线飞。
0 couldn't dvIzbe     
n.不能
参考例句：
  • He was so bedazzled by her looks that he couldn't speak. 她的美貌令他惊讶得说不出话来。
  • She had a blackout and couldn't remember anything about the accident. 她眼前一黑，那场事故就怎么也想不起来了。
0 didn't Xuezhc     
= did not
参考例句：
  • I didn't find the joke at all amusing. 我认为这笑话一点也不可笑。
  • I didn't eat any meat. 我一点儿肉也没吃。
0 during Dr7x3     
prep.在…期间，在…时候
参考例句：
  • What did you do with yourself during the summer holidays?暑假你是怎样度过的？
  • London is full of visitors during May and June.五六月间伦敦挤满了游客。
0 earth ar7xL     
n.陆地；大地；地球
参考例句：
  • The earth moves round the sun.地球绕着太阳转。
  • Spring returns to the earth.大地回春。
0 even EiUzR     
adj.平坦的，偶数的，相等的；adv.甚至，恰好，正当
参考例句：
  • It was cold yesterday,but it's even colder today. 昨天冷，今天更冷了。
  • He's the best teacher even though he has the least experience.尽管他经验最少，但教得最好。
0 fast 87ly5     
adj.快的，迅速的；坚固的；adv.紧紧地；迅速地
参考例句：
  • How fast can she run?她能跑多快？
  • It did not fly very fast.它不飞行很快的。
0 faster 2twzJx     
adj.更快的；快的( fast的比较级 )；走得快；感光快的；[摄影术]快动作的（镜头）adv.更快地
参考例句：
  • According to the theory of relativity, nothing can travel faster than light. 根据相对论，任何东西都无法超越光速。
  • Mary bragged that she could run faster than Jack. 玛丽夸口说她比杰克跑得快。 来自《简明英汉词典》
0 going dsHzY9     
n.去，离去，地面(或道路)的状况，工作情况；(复数形式）goings: 行为；adj.进行中的，流行的，现存的
参考例句：
  • We're going to listen to a report this afternoon. 今天下午我们要去听报告。
  • He hates leaving the office and going on holiday.他不愿离开办公室去度假。
0 height xlpyV     
n.高度，高处
参考例句：
  • The two trees are about the same height.这两棵树高矮差不多。
  • Prices rise to a great height.价格大涨。
0 instantaneously eqCzDW     
ad.瞬间地；即刻地
参考例句：
  • Once the cargo has been shipped, insurance can be covered instantaneously. 货物一旦发出，我会立即投保。
  • In a crash, momentum changes abruptly but not instantaneously. 在撞击过程中，动量的变化是突然的，但非瞬时的。
0 jet YaPz3     
n.喷气发动机，喷气式飞机；v.喷出，喷射
参考例句：
  • Put a match to the jet to light the gas.将火柴放在煤气喷嘴上点燃煤气。
  • I don't see the jet of your plan.我不明白你的计划的要点。
0 jets 4673f6aaf2c2048dc65e963fb8b36bf9     
n.喷嘴( jet的名词复数 )；喷气式飞机；喷射流；煤玉
参考例句：
  • The firemen directed jets of water at the burning building. 消防队员把水柱喷向燃烧着的楼房。 来自《简明英汉词典》
  • The giant jets that increasingly dominate the world's airways. 越来越称雄于世界航线的巨型喷气机。 来自《简明英汉词典》
0 life C1LxR     
n.生活；生命
参考例句：
  • The doctor came in time to save his life.医生及时来抢救他的生命。
  • At last he knew the meaning of life.终于，他知道了生命的意义。
0 light 61SxT     
n.光，光亮，灯；adj.轻的，光亮的，容易的；v.点燃，著火，变亮
参考例句：
  • The sun gives light and heat.太阳发出光和热。
  • The traffice light was green.交通信号灯是绿色。
0 lot Z0jxZ     
n.许多；好些
参考例句：
  • We had a lot of difficulties.我们碰到过许多困难。
  • Helen eats a lot of fruit.海伦水果吃得很多。
0 might BDmxl     
aux./v.(may的过去式)可能；可以，允许
参考例句：
  • It looks as if it might snow.看起来好像要下雪了。
  • Might I ask a question?我能问个问题吗？
0 Miles aoczUD     
n.英里( mile的名词复数 )；很多；一英里赛跑；大面积
参考例句：
  • Eight kilometres is roughly equivalent to five miles. 八公里约等于五英里。
  • a fortress town enclosed by four miles of ramparts 由四英里长的城墙围着的设防城镇
0 million D7QzO     
num.百万，100万；n.无数，大众
参考例句：
  • I've seen it a million times.我在书上看过无数遍了。
  • What will you do if you had a million dollars?如果你有一百万美元，你会干什么？
0 noise LGsxZ     
n.响声，喧闹声，嘈杂声
参考例句：
  • He heard a noise behind him.他听到身后有响声。
  • The noise became less and less.噪音渐渐小起来了。
0 normally ln8zVb     
adv.正常地，通常地
参考例句：
  • I normally do all my shopping on Saturdays.我通常在星期六买东西。
  • My pulse beats normally.我脉搏正常。
0 only bIzxE     
adv.仅仅，只不过；adj.唯一的；conj.可是，不过
参考例句：
  • We have only one earth.我们只有一个地球。
  • I only found it by accident.我只是碰巧找到的。
0 order iJJxt     
n.订单；命令；n.顺序，整齐；勋章；阶级，决议；vt.命令； 调整；定购
参考例句：
  • His desk is always in order.他的书桌上总是整整齐齐的。
  • You pay for it at the time you order it.订购时就得付款。
0 originated 4da2bdaa4814c619827afaf755c19446     
v.起源于，来自，产生( originate的过去式和过去分词 )；创造；创始；开创
参考例句：
  • The disease is thought to have originated in the tropics. 这种疾病据说起源于热带地区。
  • The art of portrait miniatures was originated in England. 微型画像艺术创始于英国。 来自《简明英汉词典》
0 per zMsxm     
prep.每，每一，根据，按照；由，经，以，靠
参考例句：
  • These apples cost 40 pence per pound.这些苹果每磅40便士。
  • The truck was traveling under fifty miles per hour.那辆卡车以每小时不到五十英里的速度行驶着。
0 plane eNUxX     
n.飞机；adj.平的；vi.飞行
参考例句：
  • The plane flew very high.飞机飞得很高。
  • I go there by plane.我去那儿坐飞机。
0 practical GPExc     
adj.实际的，实践的；实用的，应用的；有实际经验的
参考例句：
  • He is a practical person.他是位很讲实际的人。
  • Your invention is clever,but not practical.你的发明很巧，但不实用。
0 purposes bff9a026ac7840342f7a297fcdcd94db     
n.意志( purpose的名词复数 )；目的；作用；（进行中的）行动
参考例句：
  • I think we're talking at cross purposes; that's not what I meant at all. 我想我们是说到两下里去了，我根本不是那个意思。
  • They took a plaster cast of the teeth for identification purposes. 他们做了这副牙的石膏模型作鉴别之用。
0 quick riyyR     
adj.快的，敏捷的
参考例句：
  • Tell your brother to be quick.告诉你兄弟要快。
  • The monkeys are very quick.猴子的动作很敏捷。
0 reach 5A2z5     
n.延伸，范围，河段；vt.到达，伸出，延伸，取得联系；vi.延伸
参考例句：
  • The railway line will soon reach to our town. 铁路不久就要延伸到我们镇了。
  • Can you reach that apple down in the tree? 你能把树上那个苹果摘下来吗？
0 reaches 1345cfa89ea32b4008b6b9a8e0e9d30d     
n.河段；流域；（上、中或下）游；（外）围；（远）处；（组织或机构中的）层级
参考例句：
  • His secretary acts as a gatekeeper, reading all mail before it reaches her boss. 老板的秘书负责把关，所有邮件都由她先过目再呈送给他。
  • Traffic reaches its peak between 8 and 9 in the morning. 上午8、9点钟之间是交通高峰期。
0 reason lTYxU     
n.原因，理由，理智，道理；v.劝说，推理
参考例句：
  • That is the reason why we must go now.那就是我们现在必须走的理由。
  • The reason for the flood was that heavy rain.水灾是那场大雨造成的。
0 review xWuxR     
n.检讨，复习，回顾，评审；v.温习，检讨，评论
参考例句：
  • The newspaper gave a review of the new book.报纸对这本新书作了评论。
  • The college published a drama review.学院出版了一份戏剧评论刊物。
0 science 1Zkxe     
n.科学，学科，学问，自然科学；
参考例句：
  • Mathematics is the language of science.数学是科学的语言。
  • Is she your science teacher?她是你们的自然科学老师吗？
0 second qZTxG     
num.第二；adj.第二的；别的；n.第二；秒；片刻
参考例句：
  • Who was second in the high jump?跳高比赛第二名是谁？
  • This is the second type.这是第二种。
0 seconds 783e8e29e6a8c3e22baa58a19420eb4f     
n.助手( second的名词复数 )；第二名；秒；第二份食物v.支持( second的第三人称单数 )；临时调派；附议；赞成某提案
参考例句：
  • She ran 100m in an astonishing 10.9 seconds. 她以惊人的10.9秒速度跑完了100米。
  • The software enables you to access the Internet in seconds. 这种软件使你在几秒钟内便可访问互联网。
0 separated giszqy     
adj.分开的v.分开(separate的过去式和过去分词)
参考例句：
  • Her parents are separated but not divorced. 她父母分居但没离婚。
  • No child should ever be separated from his mother by force. 绝不能强行使任何一个孩子与母亲分开。 来自《简明英汉词典》
0 simply mymwT     
ad.仅仅,只是；简单地；朴素地；完全，简直
参考例句：
  • The cake is made quite simply.这蛋糕做起来很简单。
  • The teacher explained the text simply.老师简单地解释了一下课文。
0 slowly Qx4wE     
adv.慢地，缓慢地
参考例句：
  • Speak more slowly,please.请说慢一点。
  • Do it slowly and carefully.要慢慢仔细地做。
0 sometime CwGw2     
adv.将来某一时候；改天
参考例句：
  • He came sometime last month.上个月某个时候他曾经来过。
  • It will happen sometime and somewhere.有朝一日这总会在什么地方发生的。
0 sound Qw7wL     
n.声音，声响；v.听起来，发声
参考例句：
  • What does it sound like?它听起来像什么声音？
  • Sound travels slower than light.声音传播比光慢。
0 speed evFwb     
vt./vi（sped,sped,speeded,speeded）加快；飞跑；n.速度
参考例句：
  • The car was running at high speed.汽车急速地向前行驶。
  • We'll never get there if he doesn't speed up. 如果他不快些走，我们一定到不了那里。
0 thirty 4qtyJ     
num.三十
参考例句：
  • They were thirty in all.他们总共有三十人。
  • This book is thirty yuan.这本书三十元钱。
0 though lIRzS     
conj.虽然，尽管；即使；可是，不过，然而；adv.可是，不过，然而
参考例句：
  • It's quite pleasant today,though the wind is rather cool.尽管风有点凉，今天天气还是很不错的。
  • I will have a try even though I should fail.哪怕失败，我也要试一下。
0 toward on6we     
prep.对于，关于，接近，将近，向，朝
参考例句：
  • Suddenly I saw a tall figure approaching toward the policeman.突然间我看到一个高大的身影朝警察靠近。
  • Upon seeing her,I smiled and ran toward her. 看到她我笑了，并跑了过去。
0 traveling OgdzXo     
adj.同行的；活动的；移动的n.带球走步，走步违例
参考例句：
  • Government officials who travel on business are given traveling allowances. 因公出差的政府官员享有出差补贴。 来自《简明英汉词典》
  • The contents of the packet may shake down in traveling. 袋子里的东西经摇晃会沉到底部。 来自《简明英汉词典》
0 travelling 0m5wp     
adj.旅行的v.行进( travel的现在分词 )；步行；经过；走过…
参考例句：
  • her adventures travelling in Africa 她在非洲旅行时的冒险经历
  • She was alarmed at the prospect of travelling alone. 她一想到独自旅行的情景就害怕。
0 travels SgWzXZ     
n.旅途， （非正式）旅行笔记，游记；旅行( travel的名词复数 )；移动；游历；[机械工程]机械运动（尤指往复运动）v.行进( travel的第三人称单数 )；步行；经过；走过…
参考例句：
  • Stories about his travels abound. 有关他游历的故事多得很。
  • She travels in cyberspace by sending messages to friends around the world. 她利用电子空间给世界各地的朋友们发送信件。 来自《简明英汉词典》
0 was bglwv     
v.(is,am的过去式)是，在
参考例句：
  • He said he was right.他说他是正确的。
  • He was cold and hungry.他又冷又饿。
0 wasn't Ze2zjq     
was not的缩略式
参考例句：
  • Although the sun was shining it wasn't very warm. 尽管太阳高照，却不很暖和。
  • Please don't be angry with me. It wasn't my fault. 请别冲着我发脾气，不是我的错。

本文本内容来源于互联网抓取和网友提交，仅供参考，部分栏目没有内容，如果您有更合适的内容，欢迎 点击提交 分享给大家。