《初二物理 液體壓強 異形容器問題》由會員分享，可在線閱讀，更多相關《初二物理 液體壓強 異形容器問題（37頁珍藏版）》請在裝配圖網(wǎng)上搜索。

1、液體壓強重難點之異形杯問題 產(chǎn)生原因：液體受到重力作用，并且具有流動性公式：P=gh液體壓強 好了，廢話不多說上圖 如下圖，在質量不計、底面積相等的甲、乙、丙三個容器中，裝入相同高度的同種液體液體對容器底部的壓強P甲 P乙 P丙液體對容器底部的壓力F 甲F乙F丙容器對桌面的壓強P甲P乙P丙容器對桌面的壓力F甲F乙F丙相同高度同種液體= = = 如下圖，在質量不計、底面積相等的甲、乙、丙三個容器中，裝入相同質量的液體液體對容器底部的壓強P甲 P乙 P丙液體對容器底部的壓力F 甲F乙F丙容器對桌面的壓強P甲P乙P丙容器對桌面的壓力F甲F乙F丙相同質量 = = = 如下圖，在質量不計、底面積相等的甲

2、、乙、丙三個容器中，裝入相同質量的不同液體并使液面在相同高度處液體對容器底部的壓強P 甲 P乙 P丙液體對容器底部的壓力F甲F乙F丙容器對桌面的壓強P甲P乙P丙容器對桌面的壓力F甲F乙F丙相同高度相同質量不同液體 = = 總結一下先算壓強，后算壓力 1.肯定式：There _ + a/an 可數(shù)名詞單數(shù)/不可數(shù)名詞There _ + 可數(shù)名詞復數(shù)There _ a handsome man in the classroom.There _ an egg on his head. There _ some orange juice in the glass.There _ some lovely

3、 girls in the classroom. There is_There are _ 2.否定式： There be + not + 主語 + 其他 There _ a computer in my bedroom. =There is no computer in my bedroom. There _ any students in the classroom. =There are no students in the classroom.not a/an = no not any = no 3.一般疑問句： 一般情況：將be 動詞提前。 含情態(tài)動詞（如：will），則將情態(tài)動詞提

4、前。 There is some milk in the glass. Is there any milk in the glass? 杯子里有牛奶嗎？ 肯定回答： Yes, there _. 是的，有。 否定回答：No, there _. 不，沒有。 There will be a party tomorrow evening. _there _ a party tomorrow evening? 明晚將有一個派對嗎？ 肯定回答：Yes, there _. 是的，有。 否定回答：No, there _. 不，沒有。 注意：some疑問變any 4. there be句型中對數(shù)量進行提問 _

5、對可數(shù)名詞復數(shù)進行提問。 e.g. There are five birds in the tree. 樹上有5只鳥。 _ are there in the birds? _ 對不可數(shù)名詞進行提問。 e.g. There is a little water in the bottle. _ is there in the bottle? 練習一下（先熟悉筆記+后做題 共7分鐘）單選（7道）( ) 1. There _ some books on the sofa. A. has B. is C. have D. are( ) 2. _ children are there in the par

6、k? There are twelve children in the park. A. How many B. How much C. How number D. What many( ) 3. _ there any juice in your glass? No, _. A. Are; there arent B. Is; there isnt C. Are; there not D. Is; there not( ) 4. There _ a big tree near my house last year. A. is B. are C. was D. were ( ) 5. Wil

7、l there be a birthday party for you next week? Yes, _. A. there is B. will C. there be D. there will( ) 6. There _ any food in the kitchen. A. isnt B. is C. are D. arent( ) 7. There _two cups of tea on the table. A. is B. are C. have D. has 完成句子1. There is some soup in the bowl. （改為否定句）(1) _ _ _ sou

8、p in the bowl.(2) _ _ _ soup in the bowl.2. There are four seasons in a year. （改為一般疑問句，并作肯定回答） _ _ _ _ in a year?Yes, _ _.3. There are five people in Lilys family. （對劃線部分進行提問）_ _ people _ _ in Lilys family? 考點來了There be肯否疑問There be 就近原則 There be 是個近視眼 若句子中有幾個并列主語時，be動詞的形式要與離其最近的一個主語在人稱和數(shù)上保持一致。就近原則 T

9、here be 是個近視眼 There _ a desk and fifty-five chairs in the classroom. A. are B. is There _ fifty-five chairs and a desk in the classroom. A. are B. is 選擇正確的be動詞There _ an apple on the table. 桌子上有一個蘋果。There _ some water in the cup. 杯子里有一些水。There _ five apples on the table. 桌子上有五個蘋果。There_ one boy and

10、two girls in the classroom. 教室里有一個男孩和兩個女孩。There _ two girls and one boy in the classroom. 教室里有兩個女孩和一個男孩練習一下（共4分鐘） 單選（4道）( ) 1. Whats in your bedroom? There _ a computer, two chairs and a bookshelf in my room. A. are B. be C. has D. is( ) 2. _some toys and a book on the shelf. A. There are B. There i

11、s C. There was D. There were( ) 3. _ some milk and an egg on the table. A. There are B. There is C. There was D. There were( ) 4. _ an orange and two apples in the basket. A. There are B. There is C. There was D. There were 易錯點注意！1. 過去時 There _ a cinema in our city two years ago. 兩年前，我們城市有一家電影院。Ther

12、e _ many trees here five years ago. 五年前，這里有很多樹。There be的時態(tài)變化2. 將來時 There _ an English party next Saturday. There _ a concert this Saturday. 考點來了There be肯否疑問There be 就近原則there be和have的區(qū)別 He has some money.There is some money on the table. there be 表示存在，意為“某地/某時有”經(jīng)常與地點狀語或時間狀語連用；There is a meeting ever

13、y evening.There are some legs in the classroom.have 表示擁有，即“某人有”I have a round face .Mr. Wu has a square face. 用there be或have/has填空1. I _ a good father and a good mother.2. _a Tia on the desk.3. He _ an iPad.4. _a basketball on the playground.5. She _ some dresses.6. They _ a nice garden.7. What do y

14、ou_?8. _a reading-room in the building?9. What does Mike_? 10. _any books in the bookcase? 練習一下 考點來了There be肯否疑問There be 就近原則there be和have的區(qū)別 Lets practice！練習一下 單選(10道)（共10分鐘）( ) 1. Jack _ a big schoolbag. _ many pencils in it. A. has; There is B. have; There are C. has; There are D. have; There is(

15、 )2. Are there any maps on the wall? _ A. There are some. B. Yes, there is. C. Yes, there is one. D. No, there are. ( )3. How many _ are there in the picture? A. woman B. women C. buy D. milk ( )4. There arent _ trees near the house. There is only one. A. any B. some C. many D. much ( )5. There _ tw

16、o bowls of rice on the table. A. is B. have C. has D. are ( )5. Are there _ houses near the river? Yes, there are_ . A. some, some B. any, some C. any, any D. some, any( ) _ no coffee left yesterday. A. It being B. There being C. It was D. There was( ) 7.There are few _ in the fridgeLets go and buy

17、some peas and cabbages Avegetables Bfruit Cmeat Deggs( ) 8.Look！There are some _ on the floor Achild Bwater Cboxes Dgirl( ) 9There _ a football game in our school Ahas Bwill have Cwill be ( ) 10There is _ food hereWell have to buy some Aany Bsome Cno 完成句子1. I have three crayons in my schoolbag. （用th

18、ere be句型改寫成同義句）_ _ _ _ in my schoolbag.2. His uncle has some new story-books.（改為一般疑問句） _ his uncle _ _ new story-books?3. There is a woman near the house.（變復數(shù)） There _ _ _ near the house.4. There are some buses near the hill.（變單數(shù)） There _ _ _ near the hill. 六、when引導的 時間狀語從句 什么是when引導的時間狀語從句呢？ 用when引

19、導的一個句子來表示時間概念，則為時間狀語從句。 翻譯為“當.的時候”I could swim when I was 7. 當我7歲的時候，我就會游泳。My mother is cooking when I get home. 當我到家的時候，我媽媽正在做飯。 Jenny will come to China when she has time. 當詹妮有時間的時候，她就會來中國.Will you meet Danny when he comes? 當?shù)つ醽淼臅r候，你要見見他嗎？ 1.熟背筆記，整理筆記中題2.每天一閱讀3.天天練必刷800there be句型部分 Day1 Day2 Day3 Day4 Day5