Fermi question费米问题,理科生的脑筋急转弯 fermi level

费米问题,理科生的脑筋急转弯查看原文

太平广记卷第二百一十五,名为“算术”(我觉得这个“术”字像是法术的意思),里面记载了这样一件事儿:

后唐袁弘御为云中从事,尤精算术。同府令算庭下桐树叶数。即自起量树,去地七尺,围之。取围径之数布算。良久曰:“若干叶。”众不能覆。命撼去二十二叶,复使算。曰: “已少向者二十一叶矣。”审视之,两叶差小,止当一叶耳。……(出《稽神录》)

 

说的是后唐有个叫袁弘御的人挺会算术。哥儿几个想考考他,于是把他带到院子里,问眼前的桐树上有多少片叶子。他就神神叨叨的开始又丈量桐树,又算直径的。过了许久,他说:“若干片树叶。”这个回答倒是有点周星驰的风格。也该着他的哥们儿有主意,从树上弄掉了22片叶子,然后又把袁弘御叫来,让他算。袁弘御说:“树叶比刚才少了21片。”哥儿几个一听,心想:可不,刚才弄掉的叶子里面有两片很小的,八成人家袁老师把它俩当成一片儿算了,佩服佩服。

袁老师的算法太神秘了,一般人学不会。我倒是听说过一种估算树叶数目的方法,简单易学。

1)通过目测得知树冠的高度,半径,用球体表面积公式算出总面积A。

2)因为树叶是用来完成光合作用的,假设每一片叶子都可以得到光照,那么,所有的叶子铺开来组成的面积也是A。

3)取下一片叶子,目测估算一下叶片面积B,树叶数就是A/B。

估算的结果只要求数量级准确,因为对一棵树而言,10,000片树叶和10,021片树叶没什么不同,九牛五毛的差别。估算这个游戏,玩儿的是推导过程——学术点儿的说法叫“建模”。推导时要抓大放小,用白描的方法粗线条勾勒,让人一眼能分出来是美女还是张飞便可,没必要画出来美女胸部是什么罩杯,张飞菊花旁有几颗痔疮。估算对计算能力的要求最低(加减乘除四则运算足以应付),其次是知识储备,而对知识运用的能力要求最高——如何用简单的常识去解释看上去八杆子打不着的现象。这一点知识迁移就犹如文章里一则巧妙的比喻,颇值得玩味,比如在刚才那个估算树叶数目的例子里,光合作用的运用,给人眼前一亮的感觉。

估算领域,最有名人物的是物理学家费米。费米在理论物理和实验物理两个领域都建树颇丰,即使在物理学家群星灿烂的上世纪中期,这样的人才也没几个。费米最著名的一次估算是他在领导的曼哈顿计划中估算核爆当量的。1945年7月16日早上5点半左右,原子弹引爆成功时,费米呆在距离爆炸中心10英里处。爆炸40秒后,爆炸的气浪到达费米所在地,他将事先准备好的碎纸片从离地六英寸高的地方洒落,纸片被气浪卷走,他根据纸片飞行的距离(两米半)估算了核爆炸的“当量数”约为十万吨TNT炸药。后来证明这个结果和仪器测量值十分接近。(这里是费米对当时场景的自述原文)。

我也试着算了一下:

1)假设纸片做自由落体运动,初速度相当于气浪的速度,这个计算在初中物理习题中常见。

2)假设原子弹爆炸能量全部转化为空气的动能,爆炸之后,气浪形成球面向各个方向扩展,扩展到费米所在地时,球体内总的空气质量可以通过空气密度乘以球体体积算出来。

3)总能量等于气浪速度平方乘上空气质量。然后转换为TNT当量单位,完成。

当然,这不一定是费米原来的解法。

费米不仅自己估算,还喜欢出题给学生算,问题稀奇古怪,比如:芝加哥有多少钢琴调音师?后来,人们把这类问题称为“费米问题 (Fermi Question)”,我觉得这很像理科生的脑筋急转弯。这类锻炼并不只是娱乐和纸上谈兵,在实际科研中也是很重要的技巧。比如在实验进行之前,估算一下实验条件,选择合理的试验设备;在实验进行当中,发现新的现象之后,估算一下大概可以用哪几种理论进行解释,然后细致的设计下一步如何做,以期鉴别各种疑似解释的合理性。

只要留心,生活中充满了艺术,美,诗意,啤酒,免费的皮萨和费米问题,就看有没有缘分。前两天在新浪微博,看见陈晓卿发的饭局照片,我说了句:“告诉我快门用的是多少,我可以算出柴静右手切东西的速度!”后来有人回复说快门是1/13秒。于是我做了下面这张图。手的速度大概是0.5米/秒,如果你此刻以这个速度走过柴老师身边,会看到一把静止的刀子。



有人看到图片以后问我为什么不去算土摩托的手速?冠冕堂皇的理由是土老师没带手链,不好判断边界。当然,除了柴老师手速,还可以算每场篮球比赛球弹出底线多少次,通过小便量算自己膀胱体积,算一下人的喷嚏对于蚊子而言相当于多少级大风之于人类,在飞机上通过地面物体的大小判断飞行高度,等等。更高级一点的,可以看看这两个例子:用微波炉和棉花糖估算光速;用一张照片估算地球半径。(更多费米问题的资源请 google “Fermi question”)

在物理学发展史上,努力提高估算的效率和精度是一个十分重要的研究方向,比如微扰论,密度泛函理论,等等。当然,处理这些较为前沿的“费米问题”时,脑筋急转一下弯可能就不太够用了,通常需要的是绞尽脑汁。

Objective目标



A "Fermi question" is a question in physics which seeks a fast, rough estimate of quantity which is either difficult or impossible to measure directly.一个“费米问题”是一个物理学问题,即追求快速,数量粗略估计这是不是很难或无法直接测量。

For example: The question "How many drops of water are there in Lake Erie?"例如:问题“问水有很多滴伊利湖?” requires an estimate of the volume of a drop, the volume of Lake Erie from its approximate dimensions and conversion of units to yield an answer.估计需要一降一的量,单位容积从伊利湖的近似尺寸和转换产生一个答案。 This answer would be an estimate hopefully accurate within an order of magnitude, ie a factor of ten.这个答案将是一个数量级的估计是准确的希望在,即10个因素。

Purpose目的

The marking scheme for these questions is best explained by an example.这些问题的扣分制的,是最好的解释了一个例子。 Suppose that the question is "What is the mass of Lake Erie", and that the "correct" answer is 10^15 kg.假设的问题是“什么是伊利质量湖”,而“正确”的答案是10 ^ 15公斤。 (ie 10 raised to the fifteenth power) (即10提高到15电源)

An answer in the range: Mark范围中的一个答案:马克

2 X 10^14 - 5 X 10^155 2 × 10 ^ 14 - 5 × 10 ^ 15 5

4 X 10^13 - 2 X 10^16 3 4 × 10 ^ 13 - 2 × 10 ^ 16 3

8 X 10^12 - 1 X 10^17 1 8 × 10 ^ 12 - 1 × 10 ^ 17 1

All questions will be marked according to this general scheme, although, of course, the actual ranges will be wider or narrower, depending on the degree of difficulty in estimating the quantities involved.所有问题将被标记按照这个总体方案,虽然,当然,实际的范围将扩大或缩小,这取决于所涉及的困难程度数量的估计。

After the answers have been marked, each team may be asked to give oral explanations of some of the answers, so you should be prepared for that.答案后已标记,每个团队可能会被要求给予答复的一些口头的解释,所以你应该准备。

Participants与会者 Team of up to six members.队最多6名成员。

Materials物料 One envelope of Fermi Questions; pencils and paper.一个信封费米问题;铅笔和纸张。

Rules规则

1. 1。 Your school team will be seated around a table.你的学校团队将坐在一张桌子周围。

2. 2。 Teams will receive an envelope containing TEN (10) Fermi questions, each on a separate sheet for distribution to team members.小组将收到一个信封,含有10(10)费米问题,每个团队成员另纸分发。 Each sheet has space for working out the question, and at the bottom is a place for the answer, along with the units in which it must be given.每个表有问题的空间进行工作了,并在底部有一个答案的地方,连同给定的单位,它必须是。 Answers given in other units will get a mark of zero.其他单位所作的答复将获得零标记。

3. 3。 Teams will be given 12 minutes to answer as many questions as possible.球队将获得12分钟回答尽可能多的问题。

4. 4。 The group of team answers will be collected at the end of 12 minutes and points will be awarded for answers within given ranges.答案组小组将收集点结束12分钟,将被授予范围内给予答复。

There are purposely more questions than can be easily answered within this time limit.还有更多的问题不是故意可以很容易地回答了在这个时间限制。 However you will answer more of them if you concentrate on estimating quantities, rather than trying to get them exactly.然而,你会回答他们,如果你更加专注于估算数量,而不是试图让他们准确。

5. 5。 Calculators are not allowed in this event.计算器是不允许在此事件。

Judging看

Version 1版本1

The marking scheme for these questions is best explained by an example.这些问题的扣分制的,是最好的解释了一个例子。 Suppose that the question is "What is the mass of Lake Erie", and that the judges' best estimate is 10^15 kg. (ie 10 raised to the fifteenth power)假设的问题是“什么是伊利质量湖”,而法官的最佳估计为10 ^ 15公斤。(即10提高到15电源)

An Answer within 应答内

a factor of 一因素

ie: an answer in the range: 即:一范围的答案是:

Mark 标志

5 5

2 X 10^14 - 5 X 10^15 2 × 10 ^ 14 - 5 × 10 ^ 15 5 5

10 10

4 X 10^13 - 2 X 10^16 4 × 10 ^ 13 - 2 × 10 ^ 16 3 3

100 100

8 X 10^12 - 1 X 10^17 8 × 10 ^ 12 - 1 × 10 ^ 17 1一

All questions will be marked according to this general scheme, although the actual ranges will be wider or narrower, depending on the degree of difficulty in estimating the quantities involved.所有问题将被标记按照这个总体方案,虽然实际范围将扩大或缩小,这取决于所涉及的学位数量的困难估计。

Judging看

Version 2第2版

Teams are required to give a three-part answer (a) the minimum possible value (b) the best estimate (c) the maximum possible value.队伍须给予三个部分答案(一)最小可能值(二)的最佳估计(c)最大的可能值。

Each of these components is scored separately according to the scheme given in Version 1 above每个组件,这些成绩分别是根据上述第1项计划给予版本

Example:例如:

Minimum Value 最小值

Best Estimate 最好的估计

Maximum value 最大值 Total Score 总成绩

Judges Answer法官解答

1x 10^15 1X的10 ^ 15

Team Answer小组的解答 1 x 10^15 1 × 10 ^ 15

8 x 10^15 8 × 10 ^ 15

2 x 10^16 2 × 10 ^ 16

Team Score比赛得分 5 5

3 3

1一

9 9

All questions will be marked according to this general scheme, although the actual ranges will be wider or narrower, depending on the degree of difficulty in estimating the quantities involved.所有问题将被标记按照这个总体方案,虽然实际范围将扩大或缩小,这取决于所涉及的学位数量的困难估计。

For one question only, you will be asked to give in addition: (a) your assumptions (b) your solution steps.对于只有一个问题,你将被要求给予此外:(1)你的假设(二)解决方案的步骤。

 

After the answers have been collected, each team may be asked to give oral explanations of some of the answers.答案后已收集,每个团队可能会被要求给予口头答复的解释部分。

How to do Fermi Questions 如何做费米问题

 

Source: Columbia University资料来源: 哥伦比亚大学

The Nobel-prize-winning physicist, Enrico Fermi, came up with this simple and intuitive way to deduce the circumference of the earth.诺贝尔文学奖得主物理学家恩里科费米,想出了这个简单而直观的方式来推断地球的周长。

1. 1。 How many time zones do you pass through when you fly from New York to Los Angeles?多少个时区,你当你穿过纽约飞往洛杉矶的新?

Answer, 3答3

2. 2。 How many miles is it, about, over that same distance?它是多少英里,大约有超过同样的距离?

Answer, about 3000.答,约3000人。

3. 3。 How many miles per time zone, on average?如何每次多英里区,平均?

Answer, about 1000答,约1000

4. 4。 How many time zones must there be around the world?多少个时区,必须有世界各地的?

Answer, 24 because there are 24 hours in a day答案,因为有24天24小时

5. 5。 How many miles around the world?多少英里世界各地?

Answer, 24 time zones x 1000 miles per time zone = 24000 miles答,24个时区,每时区× 1000 =二四○○○英里英里

Yes, it is about 24000 miles around the world.是的,这是世界各地的约24000英里。

So how do I get the diameter of the Earth所以,我怎么获取地球直径

1. 1。 the formula for a circle is 2 pi r, right?为一个循环的公式是2皮?,对不对? where r is the radius and pi is about 3其中r是半径和圆周率约为3

2. 2。 so 24000 mi = 2 x 3 xr = 6 xr因此24000米= 2 × 3 = 6 XR的XR型

3. 3。 therefore 24000 mi / 6 = r = 4000 mi因此,24000米/ 6 = r的= 4000米

4. 4。 the diameter of the earth is 2 xr = 8000 mi, where the diameter is 2 times the radius地球的直径为2 XR的= 8000米,其中直径为半径的2倍

5. 5。 1 mi = 1.6 km so 8000 mi x 1.6 km/mi = 12800 km 1英里= 1.6公里等8000米× 1.6公里/英里=一二八〇〇公里

(the correct answer is ~12742 km) (正确答案是?12742公里)

So you can always figure out the dimensions from your basic knowledge of traveling!所以,你总是可以找出旅游的尺寸基本知识,你的!

 

Fermi Questions 费米问题

1. 1。 How much has the mass of the human population on the earth increased in the last year?有多少地球质量对人类的人口在过去一年有所增加? (kilograms) (公斤)

2. 2。 If the mass of one teaspoon of water could be converted entirely into energy in the form of heat, what volume of water, initially at room temperature, could it bring to a boil?如果水质量的1茶匙完全可以转换成能量的热能的形式,什么量的水,温度在室温初期,它可以把煮沸? (litres). (公升)。

3. 3。 How much does the Thames River heat up in going over the Fanshawe Dam?多少热起来的泰晤士河大坝将在范肖? (Celsius degrees). (摄氏度)。

4. 4。 How much energy does a horse consume in its lifetime?多少能源消耗做了马在其一生? (joules) (焦耳)

5. 5。 What is the weight of the air over Lake Superior?什么是空气的重量比苏必利尔湖? (Newtons) (牛顿)

6. 6。 How many joules of chemical energy are there in one litre of gasoline?如何焦耳的化学能多有一公升汽油的? (Joules) (焦耳)

7. 7。 How many bricks are there in (London)?有多少砖是在(伦敦)? (a number) (数字)

8. 8。 What is the mass of all the automobiles scrapped in North America this month?什么是集体所有这一切月份在北美的汽车报废? (kilograms) (公斤)

9. 9。 How many air molecules in an automobile tire?如何在众多的汽车轮胎空气分子? (a number) (数字)

10. 10。 How many photons/sec are emitted by a 100 watt light bulb?多少个光子/秒的排放由100瓦灯泡? (a number) (数字)

11. 11。 How long would it take a paramecium to swim from London to Toronto? (seconds)它需要多长时间一个草履虫游从伦敦到多伦多?(秒)

12. 12。 How many cells are there in the human body?有多少细胞在人体内? (a number) (数字)

13. 13。 How many oxygen molecules enter your lungs on each inhalation? (a number)多少个氧分子进入你的肺部吸入每个呢?(1号)

14. 14。 How many kilometres of DNA are there in the cells of one human body?究竟有几公里的DNA在人体内的细胞呢? (kilometres) (公里)

15. 15。 How many dollars would each person on this planet possess if there were a "mole" of dollars to distribute?多少美元将每个人在这个星球上如果有一个拥有“摩尔美元”的分配? (a number) (数字)

16. 16。 How many meters would a ground state electron in a hydrogen atom be from its nucleus if the nucleus of the hydrogen atom was blown up to the size of a baseball?多少米,地面将氢原子中的电子态从它的核心,如果氢原子的原子核在被炸毁的棒球大小的一? (metres) (米)

17. 17。 How many water molecules are there in a totally filled olympic size swimming pool?多少个水分子中有一个完全充满奥林匹克规模的游泳池? (a number) (数字)

18. 18。 To what height could loose leaf paper be stacked if you possessed Avogadro's number of sheets?到什么高度可以活页纸张叠放,如果你拥有阿伏伽德罗的张数呢? (metres) (米)

19. 19。 How many years would it take for MacDonalds to sell a mole of their hamburgers?如何将它需要许多年的麦当劳出售汉堡包痣的? (years) (岁)

20. 20。 How many atoms of iron are there in a sewing needle?如何铁原子有许多在一缝纫针? (a number) (数字)

21. 21。 How many litres of gasoline are used in your home town in one week?如何多公升汽油中使用你的家乡在一个星期? (litres) (升)

22. 22。 How many electrons could a fully charged 12 volt car battery release before it was completely discharged?多少个电子能够完全充电的12伏汽车电池释放之前,这是完全出院? (a number) (数字)

23. 23。 How many gas molecules are there in the earth's atmosphere (a number)有多少气体分子有在地球大气层(1号)

24. 24。 How many sodium ions are in one tablespoon of salt?多少个钠离子的盐在一汤匙? (a number) (数字)

25. 25。 What volume of hydrogen gas measured at STP could be produced by the electrolysis of all the water in Lake Erie?什么气体体积的氢气可计量,污水处理厂所产生的水的电解的所有伊利湖? (litres) (升)

26. 26。 When the island of Krakatoa was destroyed by a volcanic eruption, the sound waves could be detected world wide.当喀拉喀托岛是一个火山喷发摧毁,声波可以发现世界各地。 How long would it take for such a wave to travel around the earth and come back to Krakatoa?它需要多长时间这种波环游地球和喀拉喀托回来? (seconds) (秒)

27. 27。 If fighter pilots experience too high "gee" forces in a turn they black out.如果战斗机飞行员经验哎呀“势力在转弯过高”,他们黑了。 What is the minimum safe vertical turning circle for a plane travelling at the speed of sound?什么是最低安全垂直转向良性循环的速度行驶在一个平面上? (metres) (米)

28. 28。 Estimate the mass of lead deposited each year in London due to emissions from automobiles.估计导致每年大量存放在伦敦,由于汽车排放的废气。 Each litre of gas contains about 2 grams of lead.每公升的气体含有铅约2克。 (kilograms) (公斤)

29. 29。 How many piano tuners are there in Toronto?有多少钢琴调音师有在多伦多? (a number) (数字)

30. 30。 How many electrons are there in the electron beam between the cathode of your TV set and the screen?有多少个电子在电子束在屏幕上和阴极之间的你的电视机?

31. 31。 What is the thickness of this paper in wavelengths of visible light?什么是光厚度可见这种纸在波长? (a number) (数字)

32. 32。 Calculate the gravitational attraction between a man and a woman as they stand talking to each other.计算一个女人之间的引力吸引,因为他们站在人与对方交谈。 (newtons) (牛顿)

33. 33。 A weather balloon is one metre in diameter and filled with helium. What is its diameter when taken to the bottom of the Atlantic Ocean? (metres)气象气球是一个直径一米和氦气填充。什么是它的直径时采取的海洋底部的大西洋?(米)

34. 34。 There are approximately 1.5 x 10^9 cubic kilometres of ocean. If the water was to evaporate, what mass of minerals would remain behind?大约有1.5 × 10 ^ 9海洋立方公里。如果水被蒸发,什么矿物质量仍然落后? (kg) (公斤)

35. 35。 People crowd into London until all available open space within the city limits is covered with standing people.人民群众到伦敦,直到所有可用的城市范围内的空地上覆盖着站立的人。 How many people would there be?将有多少人呢? (a number) (数字)

Source: Richard K Curtis 来源: 理查德柯蒂斯K表

36. 36。 How many golf balls will fit in a suitcase?多少个高尔夫球会装在手提箱里?

37. 37。 How many hairs are there on a human head?有多少头发上人头?

38. 38。 How many individual frames are needed for a feature length motion picture?多少个人帧都需要一个功能长度电影?

39. 39。 What is the ratio of spacing between gas molecules to molecular diameter in a gas at standard temperature and pressure?什么是气体分子之间的间距比在气体的分子直径在标准温度和压力?

40. 40。 How many seconds are there in a year?有多少秒在1年?

41. 41。 If your life earnings were doled out to you by the hour, how much is your time worth per hour?如果你的生活盈利为你施舍了按小时,有多少是值得每个小时的时间?

42. 42。 What is the weight of solid garbage thrown away by American families each year?什么是垃圾重量的固体投掷距离美国家庭每年?

43. 43。 How many molecules are in a standard classroom?多少个分子在一个标准的教室?

 

Source: Prof. LB Weinstein, Old Dominion University. 来源: 温斯坦教授磅,奥多明尼昂大学。

Physicists should be able to estimate the order-of-magnitude of anything.物理学家应该能够估计订单的,什么幅度。 How many atoms of Julius Caesar do you eat every day? How much waste does a nuclear power plant generate?如何凯撒大帝许多原子你吃的每一天?多少废物不产生核电厂?

 

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General Estimation (no physics required) 一般估计(没有物理要求)

44. 44。 How many pieces of popcorn does it take to fill a room?如何爆米花多件是否采取以填补一个房间?

45. 45。 How many 1 gallon buckets of water are needed to empty Loch Ness?多少个1加仑的水水桶是空的需要尼斯湖?

46. 46。 How much dental floss does a prisoner need to escape over a wall?多少牙线确实需要一个囚犯逃离了墙?

47. 47。 What is the volume of human blood in the world?什么是人类的血液量在世界上? How does this compare to the volume of the valley at Har Meggido (Armaggedon)?这怎么比较的)量Armaggedon山谷在Har Meggido(?

48. 48。 How fast does human hair grow (in km/hr)?如何快速增长,人的头发是否公里/小时()?

49. 49。 How fast do humans grow (in km/hr)?人类怎样的速度增长(单位:公里/小时)?

50. 50。 How many atoms are in the human body?多少个原子,在人体内?

51. 51。 What is the spacing of these atoms?什么是这些原子间距?

52. 52。 Cannibalism is frowned on in most human societies.吃人是最不赞成在人类社会。 How many atoms of your great^n-grandfather who lived about 2000 years ago do you ingest with each meal?如何每餐许多原子您的伟大^欧米茄祖父谁生活在大约2000年以前,你摄取呢?

53. 53。 If all the people of the world were crowded together, how much area would we cover?如果全世界所有人民的人挤在一起,我们多少会覆盖面积?

54. 54。 Assuming one Santa Claus visits all Christian children on Christmas, how fast would he have to travel?假设一个孩子圣诞老人在圣诞节访问所有的基督徒,如何快速将他要旅行?

55. 55。 How many reindeer would he need to pull his sleigh?如何将他需要许多驯鹿拉雪橇的?

56. 56。 What is the flow rate of the James River?什么是詹姆斯河的流量? Of the Mississippi River?在密西西比河?

58. 58。 How many people were at the Million Man March in Washington DC?有多少人在百万人游行在华盛顿? How would you estimate this?你将如何估计呢?

59. 59。 How much carbon-dioxide does a square kilometer of forest remove from the atmosphere each year?多少二氧化碳并平方公里的森林从大气中除去每年?

60. 60。 How much carbon-dioxide does an automobile add to the atmosphere each year?多少二氧化碳并增加汽车每年的气氛?

61. 61。 How much carbon-dioxide does a human add to the atmosphere each year (by breathing)?多少二氧化碳做了人类向大气中添加(通过呼吸每年)?

62. 62。 How many dump truck loads would it take to cart away Mt.泥头车装载多少将它采取的车离开了山。 Everest?珠穆朗玛峰?

63. 63。 What is the mass of the Earth?什么是地球的质量?

64. 64。 What are the relative sizes (radii) of the moon and the sun?什么是相对尺寸(半径月亮和太阳)?

Transportation 运输

65. 65。 What is the relative cost of fuel (per kilometer) of rickshaws and automobiles?什么是燃料的相对成本公里(占)的人力车和汽车?

66. 66。 What is the relative waste generated (per kilometer) of rickshaws and automobiles?什么是相对的废物产生(每公里)的人力车和汽车?

67. 67。 What is the average cost of an automobile including overhead (maintenance, looking for parking, cleaning, etc)?什么是平均成本的间接费用,包括汽车(维修,停车寻找,清洁等)?

68. 68。 What is the average cost of a bicycle?什么是一个自行车的平均成本?

69. 69。 How much time would be saved nationwide by increasing the speed limit from 55 to 65 mph?多少时间将节省全国范围限制从55增加至65英里的速度? How does this compare to the extra lives lost?这怎么比较的额外的生命失去了什么?

70. 70。 How far does a car travel before a one molecule layer of rubber is worn off the tires?不多远汽车旅行前一个分子层橡胶轮胎磨损过?

Mechanics 力学

71. 71。 If comet Shoemaker-Levy had hit the Earth, how much energy would it have deposited?如果彗星苏梅克- Levy已经击中地球,将有多少能源已交存? How does this compare to one year of solar radiation?这怎么比较1年太阳能辐射?

72. 72。 How long would it take a solar sail powered spaceship to travel to a) the Moon, b) Mars, c) Pluto?它需要多长时间一个太阳帆动力飞船前往1)月球,B)的火星,三)冥王星?

73. 73。 How much work is done climbing a mountain (in kcal)?做多少工作是在攀登千卡山()?

74. 74。 How long would a beanstalk (elevator to geosynchronous orbit) have to be?多长时间一青苗(电梯地球同步轨道)要? What tensile strength would it require?什么将它的拉伸强度要求? How does this compare to steel, kevlar, spider silk, the maximum theoretical material strength?这怎么比较钢铁,芳纶,蜘蛛丝,最大理论材料的强度?

75. 75。 What is the mass of the Earth?什么是地球的质量?

76. 76。 What is the mass of the moon?什么是月球质量?

77. 77。 What is the rotational angular momentum of the Earth?什么是地球的旋转角动量?
Fermi question费米问题,理科生的脑筋急转弯 fermi level

78. 78。 What is the rotational angular momentum of the Moon?什么是月球的旋转角动量?

79. 79。 What is the maximum angular velocity the Earth could have without flying apart?什么是最大角速度地球飞行之外,完全没有?

80. 80。 What is the tidal drag force on the Earth?什么是地球上的潮汐引力作用?

81. 81。 What is the revolutionary angular momentum of the Earth about the sun?什么是革命的太阳角动量对地球?

82. 82。 What is the revolutionary angular momentum of the Moon about the Earth?什么是革命的月球的角动量对地球?

83. 83。 What is Roche's limit (the orbital distance inside which a moon will disintegrate)?什么是罗氏公司的限制(轨道距离内部有一个月亮会瓦解)?

84. 84。 How long was the day when the moon was at Roche's limit?多久那一天时,月亮在罗氏公司的限制是什么?

85. 85。 How long will the day be when it is equal to the month?多久的一天时,等于一个月?

86. 86。 According to one hypothesis, 20% of the mass of the asteroid that killed the dinosaurs was uniformly deposited over the surface of the Earth at a density of 0.02 gm/cm^2.根据一种假设,20%的恐龙的小行星的质量,炸死了均匀沉积在地球表面的密度在2 0.02克/厘米^。 What was the mass of this asteroid?什么是小行星质量呢?

87. 87。 What is the kinetic energy of a large (1 km^3) meteor?什么是动能的一大(1公里^ 3)流星? How does this compare to one year's insolation of the Earth?如何比较这一年的地球日照的? How much is this in megatons?这是多少兆吨吗?

88. 88。 How much would a large (1 km^3) meteor strike change the angular momentum of the Earth?多少钱一大(1公里^ 3)流星罢工改变地球的角动量?

89. 89。 How much energy is required to boil the Earth's oceans?需要多少能量煮地球上的海洋?

90. 90。 How often is the moon struck?往往是如何发生的月亮?

91. 91。 How large a collision is needed to split the moon in half?如何大碰撞分裂,需要在月球的一半? To split Phobos in half?要分割一半的火卫一的?

92. 92。 How small do you have to be to walk on water?你如何小,必须在水面上行走?

93. 93。 How high can mice and elephants jump?能有多高,老鼠和大象跳?

94. 94。 How large a moon can you jump off of?如何大的月亮你能跳什么呢?

95. 95。 What is the kinetic energy of a drifting continent?什么是大陆漂移的一个动能?

96. 96。 What is the height above the surrounding water of the Gulf Stream?什么是高于周围水的墨西哥湾流的高度?

97. 97。 What is the depth below the surrounding water surface of the water surface over the Marianas Trench?什么是海沟深度超过马里亚纳群岛低于水面的周围水面的?

98. 98。 How much would the ocean surface rise if the ice caps melted? How much would that change the salinity of the ocean?多少会有所上升的海洋表面的冰融化?多少会改变海洋盐度的?

99. 99。 How much would the ocean surface rise due to global warming (in addition to ice cap melting)?多少会引起海洋表面,由于全球变暖融化(除了冰帽)?

100. 100。 Astrology claims that the position of the planets at the time of our birth influences our lives.占星声称,出生行星的位置在我们的时间,影响我们的生活。 Calculate the relative gravitational attraction and the relative tidal forces on a newborn baby of a) Jupiter, b) the hospital building, c) the obstetrician.计算相对引力和)木星,相对潮汐的部队一名初生婴儿二)医院的建设,三)产科医生。

Electricity and Magnetism 电和磁

100. 100。 How strong are the magnets in the SSC?多么强大都在南南合作的磁铁? In the Fermilab ring?在费米实验室戒指?

101. 101。 How long would the Earth's magnetic field last without a dynamo?多长时间地球磁场最后没有发电机?

102. 102。 What is the lifetime of a classical atom (before the electron loses 13 eV of energy to synchrotron radiation)?什么是辐射寿命经典原子(前13 eV的电子失去能量同步)?

103. 103。 What is the Schwarzchild radius of an electron?什么是电子的史瓦西半径?

104. 104。 At what distance is the magnetic field from high power transmission lines the same as a) the Earth's magnetic field?在什么距离是磁场磁场高功率传输的路线相同,1)地球? b) the magnetic field from your electric blanket?二)从你的磁场电热毯?

Quantum Mechanics 量子力学

105. 105。 What is the probability of an object suddenly jumping up from a surface?什么是表面概率的对象突然跳起来的?

106. 106。 How small can a 1 GB memory be?怎样才能少1 GB的记忆是什么?

107. 107。 What is the probability of a human diffracting as it walks through a doorway?什么是一个人衍射概率门口散步,因为它通过一个?

108. 108。 What is the probability of a human tunneling through a closed door?什么是一个人的概率门隧道通过一个封闭的?

109. 109。 You walk off of a cliff.你走了一个悬崖。 How high does the cliff have to be (assuming constant g) for you to have an appreciable probability of quantum mechanically reflecting?究竟有多高的悬崖,必须(假设常数G)为你有一个明显的概率量子机械反映?

Energy 能源

110. 110。 How long would a laser have to stay focused on a missile to ignite the chemical explosives in the warhead?多长时间了激光必须留导弹集中在点燃的炸药的化学弹头?

111. 111。 How much Uranium must the Earth contain to keep the core molten?多少地球含有铀必须保持核心熔化?

112. 112。 How long would the sun last without thermonuclear reactions?多长时间没有太阳的最后一个热核反应?

113. 113。 What is the heat output of the sun?什么是太阳的热量输出?

114. 114。 If the Sun were made out of Gerbils, the Earth would be incinerated. Explain.如果太阳出来了言鼠,地球将被烧掉。解释。

115. 115。 How much energy would be released by stellar collapse (ie: by the Sun shrinking from its present size down to a neutron star)?多少能量被释放由恒星坍塌(即:由萨恩唐从目前的规模缩小到一个中子星)?

116. 116。 How much waste (solid and gas) is created each year by a 1000-MWe coal power plant?多少废物(固体和气体)创建每年由一个1000兆瓦燃煤发电厂?

117. 117。 How much acid rain is caused each year by an unscrubbed 1000-MWe coal power plant?多少是造成酸雨每年由一unscrubbed 1000兆瓦燃煤发电厂?

118. 118。 How much waste (solid and gas) is created each year by a 1000-MWe oil power plant?多少废物(固体和气体)创建每年由一个1000兆瓦燃油发电厂?

119. 119。 How much electrical power does the US use per year?没有多少电力,每年美国使用?

120. 120。 If 10% of Californians drive electric vehicles, how many extra power plants will it take to recharge them each night?如果加州10%的驱动电动汽车,有多少额外的发电厂,才可以把他们每天晚上充电?

121. 121。 How much Iron, Glass, and Water does the US use per year?多少钢铁,玻璃,水的存在,每年美国使用?

122. 122。 How much waste does the US generate per year?不浪费多少美国每年产生?

123. 123。 How much power do humans use?人类做多大的权力呢? How does this compare to the solar energy incident on the Earth?这怎么比较对地球太阳能事件呢?

124. 124。 What is the heat output of a human?什么是一个人热输出?

125. 125。 What would be the resource value of a 1km^3 metallic asteroid?什么将是一个1公里的小行星^ 3金属资源的价值?

126. 126。 How much power would it take to desalinate enough water for Virginia Beach?多大的权力将它采取淡化弗吉尼亚海滩足够的水?

127. 127。 How much flow is needed for a 1000 MegaWatt hydropower plant?需要多少流量为1000兆瓦的水力发电厂?

128. 128。 How much coal is needed each year for a 1000 MegaWatt coal fired power plant?需要多少煤兆瓦的煤炭每年有1000发电厂?

129. 129。 How much cooling water is needed for a 1000 MegaWatt nuclear or coal-fired power plant?冷却水的多少是需要一个1000兆瓦的核或燃煤电厂?

130. 130。 How much area would a 1000 Megawatt solar power generator need?多少面积将1000兆瓦的太阳能发电的需要?

131. 131。 How much area would an orbital 1000 Megawatt solar power generator need?多少面积将一个1000兆瓦的太阳能轨道发电机的需要?

132. 132。 How big would the earth-based receiving antenna be for an orbital 1000 MW solar power generator?如何将大的地球上的接收天线是一个1000兆瓦的太阳能轨道发电机?

133. 133。 What would the power density be at the earth-based receiving antenna?什么是功率密度在地球上的接收天线? Relative to the normal solar power density?相对于正常的太阳能功率密度?

Nuclear Physics 核物理

134. 134。 How many neutrinos from the Surry nuclear power plant pass through you each year?如何电厂许多中微子从萨里核通过你每年? How many interact?多少互动? Is this harmful?这是有害吗?

135. 135。 How much high-level nuclear waste is created each year by a 1000-MWe nuclear power plant?多少高放射性核废料造成每年由一个1000兆瓦的核电厂?

136. 136。 If this waste was spread evenly over the surface of the earth, with what depth of soil would you have to mix it so that it would be safe to ingest (ie: within federal guidelines for ingestion of radioactivity)?如果这些废物是均匀散布于地球表面的,有什么样的土壤深度,你必须自己组合它,它会是安全的摄取(如:联邦内的放射性摄取指南)?

137. 137。 How long do you have to store the waste until it becomes reasonably safe?你有多久存放垃圾,直到它变得合理的安全?

138. 138。 What are the radiation levels a) in Norfolk, b) in Denver, c) in a commercial jetliner, d) near Three Mile Island at the time of the accident?什么是辐射水平a)在诺福克,b)在丹佛,c)在商业客机,d)近三哩岛事故发生时的?

139. 139。 Ten neutrinos from Supernova 1987a (which was about 150,000 light years from earth) interacted and were detected in the Kamiokanda detector.来自超新星1987A的中微子10(即约15万光年,从地球上)相互作用,被探测器检测到Kamiokanda。 If you were standing 2 AU from the supernova, what would have killed you?如果你是站在非盟从超新星2,你会杀了你?

140. 140。 What is a lower limit on the lifetime of the proton (based on the existence of life on earth)?什么是地球上下限生命的存在对寿命为基础的(质子)?

141. 141。 What is an upper limit on the energy released in cold fusion (based on the fact that it didn't kill its proponents)?什么是它的支持者上不杀也限制了它的能量释放在冷聚变(根据事实)?

142. 142。 A biologist recently claimed to have revived a 30 million year old bacteria.一个生物学家最近声称已经恢复了30万年前的细菌。 How many cosmic rays would have passed through the bacteria during the last 30 million years?宇宙射线的多少会通过细菌在过去3000万年? What is the probability that its DNA is scrambled?什么是它的DNA是可能打乱?

143. 143。 How accurately can you date dinosaur bones?你怎么能准确日期恐龙的骨头?

144. 144。 Someone places 1 Curie of uranium on your chest.有人的地方铀在您的胸部一居里。 What do you die of?你怎么死的?

145. 145。 How much is the energy content of 10 tons of 3He worth?多少是10吨的氦-3价值能量含量?

146. 146。 How much Uranium is needed each year for a 1000 MegaWatt nuclear plant?需要多少铀每年为1000兆瓦的核电厂?

147. 147。 How dangerous is Radon?氡是怎样的危险?

148. 148。 How dangerous was Three Mile Island?如何危险的是三里岛?

Search for Extra Terrestrial Intelligence . 寻找地球以外的情报 。

149. 149。 What is the dynamic range of the human eye?什么是人眼动态范围?

150. 150。 What is the typical molecular binding energy?什么是典型的分子结合能?

151. 151。 What is the maximum size of various objects?什么是各种对象的最大尺寸? Moons, planets, suns, white dwarfs, neutron stars, mammals, reptiles, bugs?月亮,行星,恒星,白矮星,中子星,哺乳类,爬行动物,昆虫?

152. 152。 How likely is the existence of an extraterrestrial civilization?怎么可能是一个外星文明的存在?

153. 153。 What is the mean distance between civilizations?什么是文明之间的平均距离?

154. 154。 How many extraterrestrial visits per year can we expect?每年许多外星人如何访问,我们才能期望?

155. 155。 What is the probability of success for the Search for Extra-Terrestrial Intelligence?什么是智能地面成功概率为额外的搜索?

156. 156。 What are the relative probabilities of dying (in the United States) of a) motor vehicle accident, b) gunshot, c) nuclear power plant accident and routine operation, d) coal power plant accident and routine operation, e) power line EM radiation, f) lightning strike, g) small meteor strike, h) large meteor strike, i) oil power plant accident and routine operation, j) plane crash?什么是死亡的概率相对国(美国)的一)机动车事故,二)受枪伤,三)核电厂事故和日常运作,D)的燃煤电厂事故和日常运作,五)电力线电磁辐射,F)的雷击,克)小流星罢工,八)大型流星罢工,我)油电厂事故和日常运作,j)的飞机坠毁?

157. 157。 What is the human power output in the radio spectrum relative to the Earth's blackbody radio radiation?什么是无线电频谱的输出功率相对人对地球的黑体辐射无线电? 158. 158。 Relative to the Sun's radio emission (black-body)?相对于太阳的射电辐射(黑体)?

159. 159。 A balloon full of freon falls to the floor.气球氟利昂全部落在了地上。 How much freon do you expect to find in the upper atmosphere?氟利昂多少钱你希望找到在大气上层?

These problems were written and collected by LB Weinstein with help from John Adam, Charles Hyde-Wright, and Marc Sher.这些问题的书面和温斯坦收集磅同赖特帮助约翰亚当查尔斯海德-,和Marc舍尔。 These problems may be freely used in classrooms.这些问题可以自由使用的教室。 They may be copied and cited in published work if LB Weinstein is acknowledged and this URL is given:他们可能被复制和出版工作中提到,如果磅温斯坦,这是公认的网址是由于:

LB Weinstein, Old Dominion University. 磅温斯坦,奥多明尼昂大学。

More from London District Science Olympics 更多来自伦敦区科技奥运

160. 160。 How many grains of sand are there on all the beaches surrounding Lake Erie?.如何砂有许多晶粒伊利湖上所有的海滩周围?。

161. 161。 How many bricks are there in London?有多少砖是在伦敦吗?

162. 162。 How many electrons do you have in your body?有多少电子你有你的身体?

163. 163。 How many snowflakes fall on UWO if the total accumulation is 10 em?多少雪花落在西安大略如果总累积时间为10? (number of snowflakes). (雪花的数字)。

164. 164。 What is the mass of all the automobiles scrapped in North America this month?什么是集体所有这一切月份在北美的汽车报废? (kilograms). (公斤)。

165. 165。 How many molecules of ink were used in the daily newspapers of Canada today?多少墨水分子中使用了许多报纸每天加拿大今天? (number of molecules). (分子数)。

166. 166。 How much has the mass of the human population increased in the last year?有多少人口大量增加了人类在过去的一年? (kilograms). (公斤)。

167. 167。 How many air molecules in an automobile tire?如何在众多的汽车轮胎空气分子? (a number). (数字)。

168. 168。 It is Hockey Night in Canada, and Londoners sit down to watch the game.这是加拿大冰球之夜中,伦敦和坐下来观看比赛。 How much water has to go over Niagara Falls to power their television sets during, the game?多少水去了尼亚加拉大瀑布,以增强其在电视机,游戏? (litres). (公升)。

:169. :169。 How many photons/sec are emitted by a 100 watt light bulb? (number of photons)多少个光子/秒的排放由100瓦灯泡?(光子数)

170. 170。 If the mass of one million molecules of water could be converted entirely into energy in the form of heat, what volume of water, initially at room temperature, could it bring to a boil?如果水质量一百万分子可以被转换成能量完全在高温形式,什么量的水,温度在室温最初,它可以把煮沸? (litres) (升)

171. 171。 What is the weight of the air over Lake Superior?什么是空气的重量比苏必利尔湖? (Newton's) (牛顿)

172. 172。 How much work is done in dragging a suitcase of clothes from Vancouver to Halifax?多少工作是在拖着箱子从温哥华到哈利法克斯的衣服? (joules) (焦耳)

173. 173。 How much power per square metre is carried by the wind on a breezy day?如何平方米大的权力,是由每一个凉风习习的风天? (watts) (瓦)

174. 174。 How much does the Thames river heat up in going over the Fanshawe Dam?多少泰晤士河热起来,纷纷对凡肖坝? (degrees Celcius) (摄氏度)

175. 175。 How much energy does a horse consume in its lifetime.做了多少能源消耗在马其一生。 (joules) (焦耳)

176. 176。 What force is required to break a blade of grass by pulling at each end?是什么力量打破拉需要在每个月底由刀片草? (newtons ) (牛顿)

177. 177。 How many joules are there in on(.- litre of gasoline?有多少焦耳关于(.-公升汽油?

178. 178。 The marathon runner starts off at the same time as the radar signal leaves the earth for ,Jupiter.马拉松选手开始了雷达信号在同一时间的树叶为地球,木星。 He stops when the echo is received back on earth.当他停止接收回声回地球。 How far does he run?他运行多远? (kilometres) (公里)

179. 179。 The Space Shuttle is in an orbit which takes it over London and then Kitchener.航天飞机在轨道,是需要伦敦一下再基奇纳。 How long does it take to get from London to Kitchener?多久才可以把从伦敦到基奇纳? (seconds) (秒)

180. 180。 How big does a seed on the ground have to be to justify a bird in flying off a tree branch to eat it?地面做了多大的种子必须证明树枝一鸟在起飞一吃吗? (kilograms) (公斤)

181. 181。 How many cars per hour can leave London on highway 401?许多汽车如何每小时可以离开公路401伦敦吗? (number of cars) (车数)

182. 182。 What is the maximum force required to hold a .25 calibre pistol steady while firing it?什么是最大的力量须持有1 .25口径手枪射击时的稳定呢? (newtons) (牛顿)

183. 183。 How many uranium atoms must undergo fission to supply electricity to an average household for one day?多少铀原子裂变,必须进行供应家庭平均一天电力1? (number of uranium atoms) (铀原子数)

184. 184。 How many people are employed delivering mail in Vancouver? (number of people)有多少人就业提供温哥华邮件?(人数)

185. 185。 What is the force exerted on a large tree by gale winds?什么是由大风风大树所施加的力? (newtons) (牛顿)

186. 186。 What would the air in this room weigh on Mars?什么会在这个房间的空气压在火星? (newtons) (牛顿)

187. 187。 How many atoms are there in the period at the end of this sentence? (number of atoms).有多少个原子在此期间在句尾本?(原子数)。

188. 188。 Suppose the electrons that strike the surface of the picture tube in your television set were actually able to travel unimpeded to the moon.假设罢工集电子,表面你在电视显像管,实际上能够不受阻碍地旅行到月球。 How long would they take to get there?他们需要多长时间到那里? (seconds) (秒)

189. 189。 If you breath on a window in the winter.如果你的呼吸上,冬天窗口。 a patch of mist will form (1i) the glass.一期将形成薄雾补丁(1i)玻璃。 What is the mass of that patch?什么是该补丁质量? (kilograms) (公斤)

190. 190。 If all the water in the world's oceans were put in a sphere, what would its radius be?如果所有的海洋水在世界上被放在一个球体,它的半径是什么? (metre") (米“)

191. 191。 a person runs up to the top of the CN tower.一个人跑到到CN塔顶。 How many ice cubes could be melted by the expenditure of the same amount: of energy? (number of of cubes)多少冰块融化可能支出的金额相同:能量?(立方数的)

192. 192。 Consider the possibility of a large country such as China organizing a "geophysical weapon", by having all the inhabitants of China jump off` chairs onto the ground at the same instant.考虑即时的可能性同一个国家的一个大椅子上,如在中国举办地面上“”地球物理武器,通过让所有居民的'中国跳下。 Assuming; that the resulting; energy could all be focussed to one point on the earth, how many kilograms of TNT would this weapon correspond to?假设,由此产生的;能源都可以将注意力集中在地球一点,有多少公斤TNT炸药将这种武器的对应? (kilograms of TNT) (公斤TNT炸药)

193. 193。 How much energy is required to get the Space Shuttle into orbit? (joules)需要多少能量得到班车进入轨道的空间?(焦耳)

194. 194。 What is the thickness of this paper in wavelengths of visible light?什么是光厚度可见这种纸在波长? (number of wavelengths) (波长数)

195. 195。 If it were actually possible for an ant to walk to the Andromeda galaxy, how long would it take it to complete the trip?如果这是真的蚂蚁可能一步行到仙女座星系,它需要多长时间才能完成它的旅行? (years) (岁)

196. 196。 Sometimes there is a certain attraction between a man and a woman when they meet, but there is always a gravitational attraction between then: Estimate the magnitude of that gravitational attraction as they stand talking to each other.(newtons)有时候是有一定的吸引力,他们满足一个男人和一个女人的时候,但总是有那么之间的引力:估计这一规模的引力吸引,因为他们的立场互相交谈。(牛顿)

197. 197。 A helium-filled balloon is 50 cm.氦填充气球是50厘米。 in diameter.直径。 What is its diameter when taken to the bottom of the Atlantic ocean?什么是它的直径时带到海底的大西洋? (metres) (米)

198. 198。 People crowd into London until all available open space within the city limits is covered with standing people.人民群众到伦敦,直到所有可用的城市范围内的空地上覆盖着站立的人。 How many people would there be?将有多少人呢? (a number) (数字)

199. 199。 It is a clear day, and the sun is shining almost straight down on the backyard swimming pool.这是一个晴朗的日子,太阳的光辉,几乎是直倒在后院的游泳池。 How much will the water temperature change in 5 minutes?多少水5分钟,温度变化吗? (^o C). (^℃)。

200. 200。 In the North-West Territories the mosquitoes can be so numerous that a person standing in the muskeg is completely covered by the insects.在西北领土的蚊子是如此众多,一个人站在了马斯基吉昆虫完全覆盖的。 How many insects would that require?如何将需要许多昆虫? (number of mosquitoes) (蚊子的数目)

201. 201。 What is the total mass of the trees in the "Forest City"? (kilograms)什么是(公斤“?大量的树木在”森林城)

202. 202。 How many earthworms will inhabit a 100 hectare pasture field? (number of earthworms)多少蚯蚓将生活在一个100公顷牧场场?(蚯蚓数)

203. 203。 Estimate the mass of lead deposited per square metre per year in London due to airborne lead emitted from cars, given that each litre of gasoline contains about 2 grams of lead.估计导致大量的铅沉积克每平方米每年在伦敦因导致空气中排放的汽车,每公升汽油因为2包含有关。 (kilograms) (公斤)

204. 204。 How much kinetic energy is converted into heat by water striking the ground on a normal city block during a typical thunderstorm? (joules)多少动能转换成热能的雷暴水典型地突出在一个普通的街区中?(焦耳)

205. 205。 How many words are there in the books in the main branch of the London Public Library?有多少个字的书在那里,在公共图书馆的主要分支的伦敦吗? (number of words) (字数)

206. 206。 If a golf ball were the size of Jupiter, how deep would the dimples be?如果一个高尔夫球大小是木星,将有多深的酒窝呢? (metres) (米)

207. 207。 How many red blood cells are there in Michael Jackson'?红血细胞的多少有迈克尔杰克逊的? (number of red blood cells) (红血细胞数)

208. 208。 You want to have a cup of tea with your peanut, butter and jam sandwich.你想有黄油,果酱夹心一杯的茶与您的花生。 You consume part of the sandwich in a special device which uses the chemical energy in the sandwich to boil the water for your tea.您为您的消费茶水的一部分,在一个三明治煮的特殊设备的使用化学能的三明治。 If this device is 100% efficient, what fraction of the sandwich is required to make your tea?如果此设备是100%有效,如何夹心分数,才能使你的茶? (fraction of a sandwich) (分数三明治)

209. 209。 Determine the number of oxygen molecules that pass in and out of the lungs of' an adult human in one day.确定数量的氧分子,通过进出肺部有一天人类在'一个成年人。 (number of oxygen molecules) (氧分子数)

210. 210。 What is the mass of the great pyramid of Cheops?什么是伟大的基奥普斯金字塔的质量? (kilograms) (公斤)

211. 211。 Calculate the number of C0 2 molecules that are produced from the complete combustion of one litre of gasoline. (number of C0 2 molecules)计算c0的数目为2分子,从每升汽油生产的一个完整的燃烧。(c0的数目为2分子)

212 . 212。 How many kittens were born in the city of London last year? (number of kittens)多少小猫出生在伦敦金融城的最后一年?(小猫数)

213. 213。 Compute the energy collecting surface area of all the leaves of a full grown maple tree.计算表面的能量收集所有槭树面积的叶子一个充分的发展。 (square metres) (平方米)

214. 214。 A space traveller on Mars observes the earth's moon.火星上的太空旅行的观察地球的卫星。 What angle will it subtend when it is closest to Mars?什么角度将它测距当它最接近火星? (degrees) (度)

215. 215。 Estimate the number of layers of molecules of rubber lost by a tire on a car each time it revolves while driving.估计数的驱动层,而围绕它的时间橡胶分子每丢失一个轮胎上车。 (number of molecular layers) (层数分子)

216. 216。 Some people are able to inscribe as many as 100 words on the head of a pin eg the Lord's Prayer How many atoms: are displaced by the letters?有些人可以登记的流离失所者的信件多达:100原子字头上一针如主很多的祷告如何?

217. 217。 How many molecules strike your nose each second?多少分子袭击你的鼻子每一秒? (number of molecules) (分子数)

218. 218。 How many 4 litre cans of yellow paint would be needed to paint a lane divider on the 401 between London and Toronto? 4黄色颜料多少升罐将需要油漆伦敦和多伦多之间的一个通道上的401分? (number of cans) (罐数)

219. 219。 Estimate the number of ethanol molecules in a bottle of Labatt's Blue.估计蓝乙醇分子的数量在一个瓶子的拉巴特。 (number of ethanol molecules) (乙醇分子数)

220. 220。 How many grains of salt in an average salt shaker?如何在盐多粒,平均盐瓶? (number of grains) (颗粒数)

221. 221。 Protons and antiprotons can completely annihilate each other, and produce energy in the form of gamma rays.质子和反质子可以完全消灭对方,并产生伽玛射线的能量的形式。 If this energy could be all converted into electricity, at what rate would the particles need to be annihilated to light a 100 watt light-bulb?如果这种能量可以全部转化成电力价格,在什么粒子需要歼灭点燃100瓦灯泡? (annihilations per second) (第二湮没每)

222. 222。 How long does it take for the electrons in a TV tube to get from the electron gun to the screen?多长时间后才会电视显像管的电子枪在一到从电子到屏幕上? (seconds) (秒)

223. 223。 If all the atoms in an elephant were put into a line, how long would that line of atoms be?如果所有的大象都在一个原子线投入1,多久会认为原子线是什么? (metre) (米)

224. 224。 Estimate how many kilograms of potatoes are eaten each year in North America.估计有多少土豆吃多公斤北美每年研究。 (kilograms) (公斤)

225 1 wire 10 cm long and 1 mm in diameter carries a current of 1 A. How long does it take the individual electrons to get from one end of the wire to to the other using a DC source? 225 1线长10厘米,直径1毫米进行其他使用直流电源电流为1甲多久它从一开始考虑到个人电子一端的导线中的? (seconds) (秒)

226 1 wire 10 cm long and 1 mm in diameter carries a current of 1 A. How long does it take the individual electrons to get from one end of the wire to to the other using an AC source? 226 1线10厘米长,直径1毫米进行其他使用交流电的电流源的一甲多久从一开始采取以个人电子一端的导线中的? (seconds) (秒)

227 What is the total kinetic energy of all the automobiles in Canada at this moment? 227什么是总动能在加拿大所有的汽车在这一刻? (joules) (焦耳)

228. 228。 What force does the earth exert on Jupiter when they are closest.? (newtons)是什么力量也对地球施加木星时,是最接近。?(牛顿)

229. 229。 How long would it take an amoeba to travel around the circumference of the earth, supposing that it moved in a straight line at top speed, and could live that long?它需要多长时间的阿米巴环游地球周长的,假设它在高速移动顶部一条直线,并能活这么久? (seconds) (秒)

230. 230。 If there were a mole of butterflies lying evenly distributed ever the earth, how thick a layer would they produce?如果有一个躺在摩尔蝴蝶有史以来的均匀分布在地上,厚厚的一层如何将他们生产? (metres) (米)

231. 231。 When the island of Krakatoa was destroyed by a volcanic eruption, the low pressure sound waves could be detected world-wide.当喀拉喀托岛是一个火山喷发摧毁,低压声波可检测世界各地。 How long would it take for such a wave to travel around the earth and come back to Krakatoa?它需要多长时间这种波环游地球和喀拉喀托回来? (seconds) (秒)

232. 232。 What is the area of Ontario?什么是安大略省的面积? (square metres) (平方米)

233. 233。 How many cells are there in an apple?有多少细胞是在一苹果? (number of cells) (细胞数)

234. 234。 A 10 year old car is badly rusted.一个10岁的车被严重锈蚀。 If it rusted at a uniform rate, estimate how many iron atoms each day combine with oxygen to form rust?如果它在一个统一的锈蚀率,估计有多少铁氧原子结合,每天形成生锈? (number of iron atoms) (铁原子数)

235. 235。 How many individual hairs does a barber cut.多少人头发做了理发师削减。 in a lifetime? (number of hairs)在一生?(毛发数)

236. 236。 How many traffic lights are there in Toronto?多少个有红绿灯在多伦多? (number of traffic lights) (灯的交通意外数目)

237. 237。 How many Si02 molecules in a grain of sand?如何在众多的沙粒测试对分子? (number of Si02 molecules) (分子数纳米SiO2)

238. 238。 How many atoms do you have in your lungs that were also in the last breath of Julius Caesar?多少个原子你有你的肺部,也有在朱利叶斯恺撒的最后一口气? (number of atoms) (原子数)

239. 239。 What is the mass of the CN tower?什么是对的CN塔质量? (kilograms (公斤

240. 240。 How many photons of visible light are emitted in a single flash of a camera flash gun?如何可见光多光子发射的是在一个单一的闪光灯闪枪的相机? (number of photons) (光子数)

241. 241。 If you were to bore a hole straight the earth from London, Ontario, you would come out how far from London, England?如果你要钻孔直接从伦敦安大略大地,你会走出多远伦敦,英格兰? (kilometres) (公里)

242. 242。 What is the mass of all the tennis racquets in the world?什么是所有世界网球拍质量? (kilograms) (公斤)

243. 243。 How many molecules in an average human body?如何在一个平均人体许多分子? (number of' molecules) (一些'分子)

244. 244。 How many swimming strokes to swim from Grand Bend to Goderich? (number of s strokes )招多少游泳游泳从大弯至哥德里契?(行程数的S)

245. 245。 How many dimples are there on a basketball?有多少个酒窝在篮球? (number of' dimples) (一些'酒窝)

246. 246。 How many ethanol molecules in a bottle of good Scotch?如何在一个良好的苏格兰威士忌酒瓶许多乙醇分子? (number of molecules) (分子数)

247. 247。 How much energy can justifiably be expended to persuade one high school student to take Physics?多少能源可以合理地花费说服一高中学生参加物理? (joules) (焦耳)

248. 248。 How much warmer is a room when there are ten people in it than when it is empty?多少温暖的房间时,有10人在这比当它是空的? (degrees C) (摄氏度)

249. 249。 What is the total daily energy requirement of' the city of London?什么是总的伦敦金融城的日常能源需求的'? (,joules) (焦耳)

250, how many worms does a rob:in eat in a dory? 250,做了多少蠕虫抢劫:在吃一德里? (number of worms) (蠕虫数)

251. 251。 How much do the brakes of a passenger car- heat up in stopping at.多少停在刹车的轿车中热起来。 a stop sign?停止的迹象? (degrees C) (摄氏度)

252. 252。 How wide a creek can a man jump with a running start?如何广泛的小溪可以与一个人跳开始运行? (metres) (米)

253. 253。 How far-can a person throw a stone?多远,可以一个人扔石头? (metres) (米)

254. 254。 What is the mass of all of the world's fingernail clippings from today'?什么是当今大规模从世界的指甲剪报所有'? (kilograms) (公斤)

255. 255。 How far away could you hear the music, if a 30 watt stereo could put all of its output power into sound?如何远离你能听到音乐,如果一个30瓦的立体声音响可以把它的输出功率为所有? (kilometres) (公里)

256. 256。 What is the speed of Titan in its orbit around Saturn?什么是土卫六在其周围土星轨道速度? (metres/sec) (米/秒)

257. 257。 How many hairs are there on a dog?有多少头发上的狗吗?

258. 258。 How many molecules will evaporate each minute from a saucepan of water left to stand in the shade on a dry summer's day?多少分子会蒸发掉的天每分钟夏天从一个锅里的立场水遗留在树荫下就干? (number of molecules) (分子数)

259. 259。 If the conversion of electrical energy to light energy is 75% efficient, how many photons are emitted per second by a 40 watt fluorescent tube?如果能转化为光能的电器是75%的效率,有多少是第二次发射光子,每一个40瓦日光灯管? (number of photons/sec) (光子/秒的数目)

260. 260。 How fast must a hummingbird beat its wings in order to hover at 4 m above the ground (number of beats/sec)如何快速,必须击败一个蜂鸟的翅膀,以4秒米悬停在离地面/(数节拍)

261. 261。 How long would it take a signal to make a round trip to the sun through inverters (IC's)?它需要多长时间一个信号,使来回的)太阳通过逆变器(IC的? (seconds) (秒)

262. 262。 On the beach at noon, with a clear sky, you made a good snapshot at f/8, and 1/500 sec/ At midnight the same scene is lit by the full moon.中午在海滩上,有一个清晰的天空,你有了一个良好的快照在f / 8和1 / 500秒/午夜时分,同一场景是点燃满月。 You want to make an equally well-exposed picture.你要作出同样也暴露图片。 You have a tripod to hold the camera for a time exposure, and the aperture can be opened up to f/2.8.你有一段时间曝光相机三脚架持有,并可以打开光圈可达f/2.8镜头。 What would be a good exposure time to try?什么将是一个很好的曝光时间来试试呢? (seconds) (秒)

263. 263。 Near the top of the atmosphere an energetic cosmic ray proton strikes a nucleus.近大气层顶部的一个充满活力的宇宙射线质子罢工细胞核。 A fast neutron emerges from the explosion, travelling straight downwards.快中子出现的爆炸,旅游垂直向下。 What is the probability that it will reach the earth's surface without having passed through a nucleus lolls?什么是它的概率将通过一个核心lolls通过地球表面的不用? (probability) (概率)

264. 264。 Estimate the total Canadian annual energy requirement.估算总加拿大每年的能源需求。 (kilograms) (公斤)

265. 265。 What is the probabilty of winning a million dollars on Who Wants to ba a Millionaire by guessing?什么是一个百万富翁的猜测probabilty赢得1万美元到巴谁想 ? Assume everyone guesses, including the audience and teh phone-a-friend.假设每个人都猜测,包括观众和打电话给朋友。

266. 266。 What is the chance from pure guessing that a team will take home the top prize on Greed?什么是贪婪的机会从单纯的猜测,一个团队将奖品带回家在上面?

267.How many eggs are consumed in an average week in the United States? 267.How许多鸡蛋平均消费在1个星期在美国?

268. 268。 How many dozens of eggs are consumed in the United States during the week that contains Easter?如何几十个鸡蛋多消耗在美国一周内包含复活节?

269. 269。 How many electrons are there on the earth?有多少个电子在地球上?

270. 270。 According to the Canadain Blood Service, how many litres of blood are donated in Canada in the average year?据Canadain血液服务,有多少公升血液捐献是加拿大在平均一年? (Hint: One unit of blood is equal to about 450 mililitres). (提示:一个血单位等于约450 mililitres)。

271. 271。 How many compact discs were shipped to record stores in the United State in 1999?有多少被运到光盘存储记录1999年在美国国家呢?

272. 272。 How many runs were scored by major league baseball teams during April 200?运行了多少取得的大联盟棒球队在4月200?

273. 273。 On average, how much energy is released when one litre of gasoline is burned?平均来说,多少能量被释放时,1公升汽油的燃烧?

274. 274。 Including the fjords, what is the length of the coastline of Norway?包括峡湾,什么是挪威的海岸线长度?

Judging看 1. 1。 The papers will be marked using the scheme described above.这些文件将被标记使用上述计划。

2. 2。 The team with the highest score wins.与得分最高的队获胜。

Enrico Fermi 恩里科费米



Enrico Fermi 恩里科费米

Enrico Fermi, 1901-1954, won the Nobel Prize in 1938 for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons.恩里科费米, 〇一年至1954年,荣获1938年诺贝尔奖中子照射他的示威,产生新的放射性元素的存在,以及他发现的有关核反应中子带来约慢。 He led the group that produced the first nuclear reactor, in Chicago in 1942.他领导的第一个核反应堆,1942年在芝加哥生产的集团。 We remember him in the Science Olympics for his skill in estimating quantities when very little information is available.可我们记得他在奥运会的是他的科学技术时,估计量的资料极少。 He once estimated the energy released in an atomic explosion by dropping little pieces of paper, and seeing where they landed down wind.他曾估计纸片释放的能量下降很少在爆炸原子弹,看到他们在那里降落下来风。

He amused his friends by inventing questions which have a whimsical quality about them; one of the most famous is "How many Piano Tuners are there in New York City?"他逗乐他的朋友们对他们的发明异想天开的质量问题,其中有1;其中最有名的是“有多少钢琴调音师市有在纽约吗?” A very readable non-scientific account of his life is given in the delightful book "Atoms in the Family", written by his wife, Laura Fermi.一个非常可读的非科学的生活叙述的是令人愉快的书刊载于“原子中的家庭”,费米写的妻子劳拉。

A "Fermi question" is thus a question which seeks a fast, rough estimate of a quantity which is either difficult or impossible to measure directly.一个“费米问题”是这样一个问题,寻求一种快速,直接测量粗略估计数量是不是很难或根本不可能。 For example, the question "How many drops of water are there in Lake Erie?"例如,这个问题:“多少水有很多滴伊利湖?” requires an estimate of the volume of a drop, the volume of Lake Erie from approximate dimensions and conversion of units to yield an answer.估计需要一降一的量,单位体积的近似尺寸从伊利湖和转换率的答案。 This answer would be an estimate hopefully accurate within a factor of ten.这个答案将是一个因素,估计有希望的十一个准确的范围内。

EDUCATIONAL RATIONALE 教育理念

Source: http://aries.phys.yorku.ca/~rothery/fermi/fermi.edu.html来源: http://aries.phys.yorku.ca/?罗里/费米/ fermi.edu.html

No one likes to hear stories of "doom and gloom" these days.没有人喜欢听故事的黑暗“厄运和”这些天。 But the current level of science literacy in North America can only be described as "woeful."但是,目前北美洲的科学素养水平只能说是“可悲的。” The long-term consequences of a largely scientifically illiterate population are very serious and ultimately debilitating to any modern society.这主要是由于科学的文盲人口的长期后果是非常严重的,并最终削弱任何现代社会。

Rather than complain interminably, some educators such as Richard Light offer thoughtful advice about how best to remedy this state of affairs, regardless of who's to blame.而不是抱怨没完没了,光提供一些教育工作者,如理查德最周到的咨询有关如何纠正这种状况的,不管是谁的责任。 Ranking very high on the list for improving critical thinking skills and scientific common sense at all levels is, Fermi Questions.排名非常高的费米问题清单思维能力和科学常识,提高关键在各级而言。

Fermi Questions build problem-solving skills and develop much-need estimation skills.费米问题建立解决问题的能力和发展极为需要的估计技能。 It is critically important that a successful student have a "feel" for whether an answer is reasonable or not.这是极为重要的,成功的学生有一个“感觉不”的答案是否合理。 The beauty of a Fermi Question is that the methodology, that is, the formulation of a solution, is more important than the answer itself: Indeed there is no "correct" answer to a Fermi Question, only a range of answers.一个美丽的问题是,费米的方法,即制定一个解决方案,是更多:重要的不是答案本身其实是没有“正确答案”一费米问题,只有一个答案范围。 Moreover, memorization of facts becomes much less important than developing the logical tools necessary to solve such questions.此外,事实的记忆变得更重要了发展问题的必要的逻辑工具来解决这样的。 The sooner students are introduced to this way of thinking in science, particularly the physical sciences, the better.越早提交本学生更好地在科学的思维方式,尤其是物理科学的。 From a student's perspective, the "coolest" thing about Fermi Questions is that they're fun, or at least can be made so relatively easily.从学生的角度来看,“最酷的问题”的事情了费米,是他们的乐趣,或者至少可以作出这样比较容易。 What more can one ask?更能够叫什么?

Finally, just what is a Fermi Question?最后,究竟什么是一费米问题吗? Philip Morrison, in a Letter to the Editor of the American Journal of Physics in 1963, said it best in the following excerpt in which he is commenting on the training of undergraduate physics majors.菲利普莫里森,在编辑的信1963年美国物理杂志的说,最好在以下摘录他在大满贯赛是在物理评论本科生的培训。 But it should be noted that Fermi Questions are appropriate for all levels of education, including elementary and secondary schools.但是,应该指出的是,费米问题是学校适合各级教育,包括小学和中学。

 

"It is by no means possible to specify the training and readiness of a prospective graduate student by a mere list of topics. There is a kind of power over the theoretical and experimental studies in which he has engaged which is difficult to define, but whose presence is perhaps more important than much knowledge which is more formal and complete. There is one test for such power which is at the same time a remarkably apt method for its development. That is the estimation of rough but quantitative answers to unexpected questions about many aspects of the natural world. The method was the common and frequently amusing practice of Enrico Fermi, perhaps the most widely creative physicist of our times. Fermi delighted to think up and at once discuss and to answer questions which drew upon deep understanding of the world, upon everyday experience, and upon the ability to make rough approximations, inspired guesses, and statistical estimates from very little data. “这是绝不可能的手段来指定准研究生课题由一个单纯的名单和培训的准备。有哪种力量在从事理论和实验研究中,他已很难界定,但其或许更重要的存在是比很多知识,更正式,完整。有一个发展权的这种测试是在同一时间恰当方法显着。这是大约估计粗糙,但定量的方式回答了许多意想不到的问题世界自然方面。有趣的方法是实践恩里科费米常见病和多发病,也许是我们这个时代的物理学家最广泛的创造性。费米高兴地想起来,在一次讨论和回答涉及吸引了世界的深刻理解后,后日常经验,并呼吁有能力做出粗略估计,鼓舞猜测,几乎没有数据统计的估计从非常。

Such questions can of course be found for nearly any level of education. [The] conception of experiments and the formation of theoretical hypotheses are activities which are well simulated by asking and answering good Fermi questions."这些问题当然可以找到几乎任何教育水平。[实验的]的概念和理论假说形成良好的费米问和回答的问题是这些活动很好地模拟了。“

 

Source来源 Enrico Fermi恩里科费米

  

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