初二物理 液體壓強 異形容器問題

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(zhì)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(zhì)量不計、底面積相等的甲、乙、丙三個容器中，裝入相同質(zhì)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(zhì)量 = = = 如下圖，在質(zhì)量不計、底面積相等的甲、乙、丙三個容器中，裝入相同質(zhì)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(zhì)量不同液體 = = 總結(jié)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 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 _ 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 park? 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. Will 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) _ _ _ soup 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 There 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 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 is 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。There _ 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 every 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 you_?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( )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 _ two 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 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there 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