第1篇：浮力计算题方法总结
浮力计算题方法总结
面对中考，考生对待考试需保持平常心态，复习时仍要按知识点、题型、易混易错的问题进行梳理，不断总结，不断反思，从中提炼最佳的解题方法，进一步提高解题能力。下文准备了浮力计算题方法总结，欢迎来参考！
浮力计算题方法总结：
（1）、确定研究对象，认准要研究的物体。
（2）、分析物体受力情况画出受力示意图，判断物体在液体中所处的状态（看是否静止或做匀速直线运动）。
（3）、选择合适的方法列出等式（一般考虑平衡条件）。
计算浮力方法：
①量法：F（浮）=G—F（用弹簧测力计测浮力）。
②力差法：F（浮）=F（向上）—F（向下）（用浮力产生的原因求浮力）
③浮、悬浮时，F（浮）=G（二力平衡求浮力;）
④F（浮）=G（排）或F（浮）=（液）V（排）g（阿基米德原理求浮力，知道物体排开液体的质量或体积时常用）
⑤根据浮沉条件比较浮力（知道物体质量时常用）
浮力的利用
(1)、轮船：
工作原理：要使密度大于水的材料制成能够漂浮在水面上的物体必须把它做成空心的，使它能够排开更多的水。
排水量：轮船满载时排开水的质量。单位t由排水量m可计算出：排开液体的体积V(排)=m/排开液体的重力G(排)=mg;轮船受到的浮力F(浮)=mg轮船和货物共重G=mg。
(2)、潜水艇：
工作原理：潜水艇的下潜和上浮是靠改变自身重力来实现的。
(3)、气球和飞艇：
工作原理：气球是利用空气的浮力升空的。气球里充的是密度小于空气的气体如：氢气、氦气或热空气。为了能定向航行而不随风飘荡，人们把气球发展成为飞艇。
(4)、密度计：
原理：利用物体的漂浮条件来进行工作。
构造：下面的铝粒能使密度计直立在液体中。
刻度：刻度线从上到下，对应的液体密度越来越大。
知识要点：
1、浮力的定义：一切浸入液体（气体）的物体都受到液体（气体）对它竖直向上的力叫浮力。
2、浮力方向：竖直向上，施力物体：液（气）体。
3、浮力产生的原因（实质）：液（气）体对物体向上的压力大于向下的压力，向上、向下的.压力差即浮力。
4、物体的浮沉条件：
（1）前提条件：物体浸没在液体中，且只受浮力和重力。
（2）说明：
① 密度均匀的物体悬浮（或漂浮）在某液体中，若把物体切成大小不等的两块，则大块、小块都悬浮（或漂浮）。
② 一物体漂浮在密度为的液体中，若露出体积为物体总体积的1/3，则物体密度为2/3。
③ 悬浮与漂浮的比较，相同：F浮 =G物：不同：悬浮液=物，V排=V物，漂浮液<物;V排
④ 判断物体浮沉（状态）有两种方法：比较（F浮）与G或比较（液）与物。
⑤ 物体吊在测力计上，在空中重力为G,浸在密度为的液体中，示数为F则物体密度为：物=G/（G-F）。
⑥ 冰或冰中含有木块、蜡块、等密度小于水的物体，冰化为水后液面不变，冰中含有铁块、石块等密大于水的物体，冰化为水后液面下降。
5、阿基米德原理：
（1）内容：浸入液体里的物体受到向上的浮力，浮力的大小等于它排开的液体受到的重力。
（2）公式表示：F浮 =G排=液V排g，从公式中可以看出：液体对物体的浮力与液体的密度和物体排开液体的体积有关，而与物体的质量、体积、重力、形状、浸没的深度等均无关。
（3）适用条件：液体（或气体）
第2篇：浮力计算题
21.—Is it _________ bag?—No, it’s an old cap
.A.theB.anC.aD.any
22.—What does your brother look like?—He is _____________.A.fine
B.Nice and friendlyC.goodD.Tall and handsome
23.—You swim so well.Who taught you?—Learn by __________.A.myselfB.herselfC.himselfD.itself
24.My mother is ill in hospital.I have to ___________ my grandparents at home.A.look outB.look afterC.look upD.look at
25.—Are you afraid of dogs?— ______________.A.Yes, I am.B.Yes, I do.C.No, I don’tD.Yes, I did.—What _______ do you choose, small, medium or large?
—Large, please.A.color.B.size
C.price.D.kind
27.—Our claroom is so clean.—It ___________ every day.A.is cleaned B.was cleaned
C.cleansD.cleaned
28.—There’s going to _______ an English evening tonight? Would you like to go with us?—I’d love to.A.have
B.hasC.isD.be
29.—What can I do for you?—_________________.A.I’m just kiddingB.I’ll take itC.I’m just lookingD.Take it easy 30.—May I play computer games, Mom?—No, you ____________.A.don’t
B.can’tC.wouldn’tD.won’t
31.—Jane, when did you come here?
—In 2010.I ___________ here for two years.A.Have been toB.Have gone toC.have comeD.have been
32.—I really hate to go to such a noisy place.—_____________.A.So am IB.So do I
C.So have ID.So can I
33.—__________ go out for a picnic next Saturday.—Good idea.A.Why notB.How about
C.Would you like toD.Let’s
34.—__________ do you go to the library?
—Twice a week.A.How soonB.How much
C.How often
D.How far
35.—I wonder ____________ at 8:00 last night?
—I was watching NBA.A.What were you doingB.What did you do
C.what you were doing
D.What are you doing
II.完形填空（10分）(阅读下面短文，然后根据短文内容，从A.B.C三个选
项中选择能填入相应空白处的最佳选项，并在答题卡的相应位置将其涂黑)
Showing your feeling is important.It is a mistake not to talk to anyone ___36_ you’re feeling sad, worried or nervous.If you keep bad feelings inside, it can even make you37 _.But if you38with someone, like your mom or dad, you’ll usually begin to feel 39_than before.Now you’re not all alone with your problems or worries.40 , it doesn’t mean your problems and worries will41magically(神奇地).But, at least, someone else understands what’s42with you and can help43find ways to solve your problems.Your mom and dad want to know if you have44.They love you and they want to know what’s happening in your life.But if you don’t want to talk with them, what should you do? Find a trustworthy(可信任的)teacher at school or a relative.Maybe that person can help you deal with your problems.Then you’ll feel as45as before.36.A.what B.when C.how
37.A.sick B.active C.strong
38.A.tell B.speak C.talk
39.A.worse B.betterC.well
40.A.Whatever B.However C.Whenever
41.A.disappear B.appear C.happen
42.A.matter B.more C.wrong 43.A.them B.you C.us
44.A.problems B.problem C.question
45.A.happily
B.bad
C.happy
III、情景交际（15分）
（1）从B栏中找出与A栏相对应的答语，并在答题卡的相应位置将其涂黑。（5分）A
B
46.Happy weekends!A.Hello!Who’s this, please? 47.Help yourself to some fish.B.Thank you very much.48.What’s the date today?C.How do you do? 49.Hello, may I speak to Mike?
D.The same to you.50.How do you do?E.June 23rd, 2013.（2）从框里选择填入对话相应空白处的适当选项,并在答题卡的相应位置将涂黑
A.I like a quiet place.B.Enjoy yourself in the countryside.C.Why do you want to live in the countryside?
D.What are you going to do in the summer holidays?
E.Because animals give us joy and can help us do some useful things
A: Hi, Darren!It’s a nice day, isn’t it? B: Yes,it is.51____
A: I plan to visit my grandparents during the summer holidays in the countryside.B:Really? 52_________
A: Because of too much noise in the city.53_________.What’s more, there are many green plants in the countryside.I like plants.B: I also like plants, but I like animals better.A:Why do you think so?
B: 54_________ They are our friends.A: I think I should also make an animal friend
A: I think I should also make an animal friend.B: 55_____________ A: Thank you
阅读理解（40分）
I、阅读理解（20分）(阅读I和II两篇短文，从56-65每小题所给的选项中选出最佳答案，并在答题卡的相应位置将其涂黑。
IWonderful Tour(4-Day)of Tongren
Overseas Tourist Corporation Guizhou China Including:
Places to visit:Price: Only ￥2,668★A round-trip(往返旅行)plane ticket from Guiyang to Tongren ★Bus service around Tongren ★Three nights’stay in good hotels ★The best tour guide service
★Ming Paradise(大明边城）—the national AAAA level scenic spots(景点）★Hot Spring in Shiqian(石阡）—enjoy spas/spring bath(泡温泉/温泉浴)★Mount Fanjing—the most famous mountain in Guizhou Office hours:
Monday-Friday8:00 a.m.-8:00 p.m.Saturday&Sunday9:00 a.m.-7:00 p.m.Tel: 0851-8630158Addre: No.28 Yanan Road Guiyang
56.From the information above, we know this is.A.a map
B.an air ticketC.a piece of news
D.an ad.(advertisement)57.You can’t enjoyin Tongren.A.taking a bus around Tongren
B.staying in good hotels
C.getting some small presents D.Receiving a good tour guide service 58.You can visit ___________ places if you take the tour.A.two
B.three
C.four
D.five 59.How can you book the tour?A.By phone.B.By writing blogs.C.By chatting with them online.D.By sending them an e-mail.60.Where can you go to book a ticket to Tongren?A.Ming ParadiseB.Shiqian
C.TV station
D.No.28 Yanan Road Guiyang
II
In the year 2050, there will be different kinds of materials for clothes.Special materials will keep the clothes clean for ever.They will never get dirty or wear out.We will have le work because we won’t have to wash them.So we can save water and money.And children won’t worry about what to wear to school every day.They won’t go to school.They’ll stay at home in front of their computers to study.They can wear their favorite “Saturday clothes” every day.It will be fun.Do you think so? What do you think school clothes and school life will be like in 2050?
61.Maybe wewash clothes in the year 2050.A.didn’tB.needn’t
C.mustn’t
D.won’t be allowed to 62.Why won’t the children go to school?A.because they’ll play at home.B.because they hate to go to school.C.because they’ll study on the Internet.D.because they’ll wash clothes to make money.63.Will the clothes get dirty in the year 2050?
A.No, it won’t.B.Yes, they will.C.Yes, it will.D.No, they won’t.64.In the year 2050, the clothes will notfor ever A.wear out or get dirtyB.wear wellC.be thinner and thinnerD.be fantastic
65.From the paage,which of the following is NOT true?A.There will be different kinds of materials for clothes.B.The children can wear their favorite clothes.C.The children always worry about what to wear.D.The children can study at home in front of their computers.II、阅读判断（10分）(根据短文内容判断66-70题的正误。正确的用A，错误的用B，并 在答题卡的相应位置将其涂黑)
Robots have been designed to do many things, such as saving people, working in a hospital, serving for us and so on.There are some robots working in the Jinjiang Robot Hotel in Tongren, Guizhou.One hundred customers can have a big dinner in it together.Two of the robots serve drinks, while the other four serve the food.But not all the work in the restaurant is done by them.There are also people working there, especially in the kitchen.The cooks are humans, because the robots don’t have the skills to cook.66.Robots can work in a hospital.67.Four robots work in the Jinjiang Robot Hotel.68.No people work in the kitchen.69.Robots can serve drinks and the food.70.The robots can cook delicious food.III任务型阅读（10分）
本部分试题在卷II（76-80小题）
卷II
听力II（10分）(听一篇短文，根据所听到的短文内容填写表格。每空一词。答案务必另 书写于答题卡卷II各小题规定的位置。)Before dinner Arrive on 71.____________You’d better bring a 72._________ gift
During dinner Just 73.________ what you want.After dinner
Don’t leave at once or stay too 74.___ ___
Call the host or write a thank-you 75.___ ___
任务型阅读（10分）(阅读下面短文，然后根据短文内容每空填写一个单词完成76—80 小题。答案书写于答题卡卷II各小题规定的位置。)
Richard, 14, said, “ I want to make friends, but I don’t know how.In my last school, my clamates often bullied(欺负)me and I didn’t have any friends.Children at this school look OK, but I just know I’ll also do something wrong.Please help me!”
Perhaps the best way to make friends is to know what makes a friend.I asked some 13-year-old boys and girls to write down they liked about their friends.They said that good friends:
★go around with happy faces.★like to share.★stay and play together with others.★invite people to do something★are humorous.★are good at organizing games.★help others with work.★are kind.★ are good at thinking of something fun to do
Good friends
go around 76.__________ happy faces like to share
stay and play together with other.77._________ others with work.are 78.________ and humorous.79.__________ people to do something.are good at organizing games and thinking of something 80._________to do
书面表达（40分）
I.单词拼写（10分）
i.根据括号里所给单词(汉语)的适当形式填空。答案书写于答题卡卷II各小题规定的位置。81.All of us should love our lives and obey the traffic __________（规则）.82.Go along this road and turn ________（左边）at the second croing.83.Farmers are often ________（忙碌的）with their harvest in autumn.84.Beijing, the capital of China, is one of the oldest ________(city)in China.85.—What’s the secret of your ________（succe）?
—Work hard.书面表达（40分）
I.单词拼写（10分）
i.根据括号里所给单词(汉语)的适当形式填空。答案书写于答题卡卷II各小题规定的位置。81.All of us should love our lives and obey the traffic __________（规则）.82.Go along this road and turn ________（左边）at the second croing.83.Farmers are often ________（忙碌的）with their harvest in autumn.84.Beijing, the capital of China, is one of the oldest ________(city)in China.85.—What’s the secret of your ________（succe）?
—Work hard.II.短文改错（10分）
下列短文的划线部分是错误的，请将其正确答案书写于答题卡卷II各小题规定的位置。Twenty years old, an old man who is over sixty91.years older, went to see his son.The son was happy to92.see his mother and picked up the phone and said,93.“Hello, bring me any good food.” A moment later,94.the beautiful girl brought the food there.95.“What magical the phone is!” the old man
96.said to himself.After a little days,he went back to his hometown97.with the phone.He picked up the phone as soon as he gets home98.and said, “Hello, some delicious food, please.” Then he waited here.99.He waited or waited.But nobody brought him anything.100
III．写作（20分）
温馨提示：（作文书写于答题卡卷II规定的位置。）
在铜仁市开展“4+2”特色教育活动中，你是怎么做的。请根据内容提示，用英语写一篇短文。
内容提示:每天早上做早操......每天课外活动时间打球、唱歌、跳舞.....每天至少运动一小时我擅长......参考词汇: do morning exercisesplay basketball/ping pongdancesong songshave at least...for sports every daybe good at/do well inwin 要求：
1.语言表达准确，语意通顺、连贯； 2.书写工整、规范；
3.根据所给内容和参考词汇，可适当发挥； 4.文中不得出现真实的校名和人名；
5.词数：70词左右。文章的开头,和结尾己给出, 不计入总词数。
Students all take an active part in Tongren Four and Two Special Education Acitivities in our school.Every morning, I
综合运用 21－55满分40分.（21－50每小题1分；51－55每小题2分；）
21.C22.D23.A24.B25.A.26.B 27.A28.D29.C 30.B.31.D32.B33.A34.C3
5.C36.B37.A38.C39.B40.B41.A
42.C43.B44.A45.C46.D47.B48.E49.A50.C
51.D52C53.A54.E55.B 阅读理解（56－70每小题2分，满分30分）
56.D57.C58.B59.A60.CD61.B62.C63.D64.A65.C 66.A67.B68.B69.A70.B
卷II
听力II（71－75每小题2分；满分10分）
71.time72.small73.eat74.long75.note 任务型阅读（76－80每小题2分；满分10分）
76.with77.help78.kind79.invite80.fun
书面表达（81－100每小题1分；作文满分20分；满分40分）I.单词拼写(10)
81.rules82.left83.busy84.cities85.succe
86.foot87.everything88.far89.twelve90.made
I.短文改错(10)91.was.92.old93.father94.some95.a 96.How 97.few
98.got99.there100.and
第3篇：八年级物理浮力计算题
东凯教育
个性化教案
浮力计算专题
1、如图15所示，容器中装有水，水中有一个木块被细线系着，已知水重200N，水深为0.5m，木块的体积为4dm，木块的密度为0.6×10kg/m，试求：
（1）水对容器底面的压强是多少？木块受到的浮力是多大？（2）若绳子断了，最终木块漂浮在水面上时，所受的浮力为多大？ 此时水对容器底的压强比第（1）问中的大还是小？ 3332、用一弹簧测力计挂着一实心圆柱体，圆柱体的底面刚好与水面接触(未浸入水)如图甲，然后将其逐渐浸入水中，如图乙是弹簧测力计示数随柱体逐渐浸入水中的深度变化情况，求：(g取10N／kg)(1)圆柱体受的最大浮力。
(2)圆柱体刚浸没时下表面受到的液体压强。(3)圆柱体的密度。
3、一个不规则的实心物体，质量55g，放入装满纯水的烧杯中，沉入底部，排开0
第4篇：八年级浮力计算题专题练习
浮力计算专题
1、如图15所示，容器中装有水，水中有一个木块被细线系着，已知水重200N，水深为0.5m，木块的体积为4dm，木块的密度为0.6×10kg/m，试求：（1）木块受到的浮力是多大？
（2）若绳子断了，最终木块漂浮在水面上时，所受的浮力为多大？ 3332、用一弹簧测力计挂着一实心圆柱体，圆柱体的底面刚好与水面接触(未浸入水)如图甲，然后将其逐渐浸入水中，如图乙是弹簧测力计示数随柱体逐渐浸入水中的深度变化情况，求：(g取10N／kg)(1)圆柱体受的最大浮力。(2)圆柱体的密度。
3、一个不规则的实心物体，质量55g，放入装满纯水的烧杯中，沉入底部，排开0.5N的水。然后向烧杯中加盐并搅拌，直到物体悬浮为止。g=10N/kg）求：（1）物体在纯水中所受的浮力；（2）物体的体积：
（3）物体
第5篇：浮力计算题专项训练答案
浮力计算题专项训练(三)例1:有一实心金属球，用弹簧测力计在空气中称得重力为3.9N，将它浸入盛满水的溢水杯中时，有50ml水从溢水杯中溢出，求：
（1）金属球的体积；
（2）金属球所受的浮力；
（3）金属球浸没在水中称时，弹簧测力计示数； 解:（1）金属球的体积： V=50ml=50cm3=5×10-5m3；（2）金属球所受浮力：
F浮=G排=ρ水gV排=1.0×103kg/m3×10N/kg×5×10-5m3=0.5N；（3）∵G=F示+F浮，金属球浸在水中时弹簧测力计的示数： F示=G-F浮=3.9N-0.5N=3.4N；
例2为安全起见，初学游泳者常使用一块泡沫浮板，用双臂把浮板压入水中，借助浮板所受的浮力来辅助游泳。已知泡沫浮板的密度是0.1×103kg/m3，体积为3000cm3。（ρ水=1
第6篇：地理计算题方法集锦
地理计算题方法集锦
2010-01-22 15:00
地理计算题方法集锦
1、比例尺＝图上距离÷实际距离
2、相对高度＝高处海拔－低处海拔
3、低处气温＝高处气温＋(高处海拔－低处海拔)÷100×0.64、高处气温＝低处气温－(高处海拔－低处海拔)÷100×0.65、气温日较差＝日最高气温÷日最低气温
6、气温年较差＝最高月平均气温－最低月平均气温
7、人口自然增长率＝出生率－死亡率或＝(出生人口－死亡人口)÷总人口×100%
8、人口密度＝地区总人口÷地区总面积(单位：人/平方千米)
几个重要判断
1、纬度小于30的：低纬度
纬度在30--60之间：中纬度
纬度大于60的：高纬度
2、西经大于20、东经大于160的：位于西半球
西经小于20、东经小于160的：位于东半球
3、等高线往山顶凹进去的：山谷
等高线从山顶凸出来的
第7篇：高中有机化学计算题方法总结(修正版)【强烈推荐】
烃、烃的衍生物完全燃烧计算技巧
1.耗氧量
CXHY和CXHYOZ混搭比较——把衍生物CXHYOZ分子式写成残基·不耗氧的CO2 · H2O后,剩余残基再跟烃CXHY比较。如比较乙烯C2H4和乳酸C3H6O3,后者就可写成C2H4•1CO2•1H2O，故等物质的量的二者耗氧量相同。
等质量的烃的含氧衍生物CxHyOz完全燃烧时，先化成 Cx Hy•mCO2•nH2O 的形式，耗氧量决定于 y'的值，此值越大，耗氧量越多； x'2.产水量
等质量的烃CxHy完全燃烧时，产水量决定于
y的值，此值越大，产水量越多； x等质量的烃的含氧衍生物CxHyOz完全燃烧时，先化成 Cx’Hy’•mCO2•nH2O 的形式，产水量决定于
3.产CO2量
等质量的烃CxHy完全燃烧时，产CO2量决定于 y' 的值，此值越大，
