4、本文的重點(diǎn)是說(shuō)辭,雖僅百余字,卻委婉曲折,步步進(jìn)逼,層層深入,表現(xiàn)出高超的勸說(shuō)藝術(shù)、游說(shuō)技巧。讓學(xué)生細(xì)細(xì)品味并概括說(shuō)辭中包含幾層意思。第一層(“秦、晉圍鄭,鄭既知亡矣”),分析形勢(shì),以退為進(jìn),博得好感。第二層(“若亡鄭而有益于君”至“君之薄也”),亡鄭陪鄰,動(dòng)搖聯(lián)盟。第三層(“若舍鄭以為東道主”至“君亦無(wú)所害”),存鄭有益,利益引誘。第四層(“且君嘗為晉君賜矣”至“唯君圖之”),追溯歷史,深入離間。可見(jiàn)燭之武面對(duì)大國(guó)的君主,巧舌如簧,不卑不亢,從容辭令,既不刺激對(duì)方也不失本國(guó)尊嚴(yán),語(yǔ)言的分寸掌握得恰到好處。表現(xiàn)出燭之武機(jī)智善辯的外交才能。5、面對(duì)風(fēng)云突變的局勢(shì),晉侯沒(méi)有感情用事,而表現(xiàn)了清醒的頭腦和理智的判斷。這種隱忍不發(fā)、隨機(jī)應(yīng)變的胸懷和謀略,正是晉文公終成霸業(yè)的根本原因。設(shè)計(jì)意圖:本環(huán)節(jié)的重點(diǎn)是全面把握燭之武這一人物性格特征,以及退秦師過(guò)程中體現(xiàn)出的非凡的膽識(shí)以及高超的謀略和語(yǔ)言藝術(shù)。
一、說(shuō)教材《短歌行》是普通高中課程標(biāo)準(zhǔn)實(shí)驗(yàn)教科書(shū)必修(二)第二單元的一篇略讀課文,本單元安排的是先秦到南北朝時(shí)期的詩(shī)歌。《短歌行》是著名政治家、軍事家、文學(xué)家曹操的作品。詩(shī)中抓住“憂”字來(lái)寫(xiě)詩(shī)人為什么“憂”,如何解“憂”,從而表達(dá)希望能夠招攬人才、完成統(tǒng)一天下的雄心壯志。所以本單元安排《短歌行》一詩(shī),對(duì)學(xué)生全面了解曹操,感受曹操在短暫的人生中竭力創(chuàng)造偉業(yè)的氣概。二、說(shuō)學(xué)生我這一課的教學(xué)對(duì)象是高一學(xué)生。他們進(jìn)入高中學(xué)習(xí)的時(shí)間只有三個(gè)多月,現(xiàn)在已經(jīng)完成了必修(一)的學(xué)習(xí)。學(xué)習(xí)了現(xiàn)代詩(shī)歌單元,有了一定的詩(shī)歌學(xué)習(xí)基礎(chǔ),初步掌握了讀詩(shī)的基本方法,但是還未能形成成熟的穩(wěn)定的學(xué)習(xí)方式。同時(shí),本單元學(xué)習(xí)是高中第一次接觸古代詩(shī)歌,詩(shī)歌語(yǔ)言上的障礙和時(shí)間上的跨度對(duì)他們來(lái)說(shuō)都是學(xué)習(xí)上的困難。因此教師要引導(dǎo)學(xué)生自主學(xué)習(xí),合作學(xué)習(xí),為他們?cè)O(shè)置新的學(xué)習(xí)情境,提供合作探究的機(jī)會(huì)。
1.必須明確政治生活的作用 (政治生活與經(jīng)濟(jì)生活、文化生活是相輔相成的。政治生活直接影響到人民民主的實(shí)現(xiàn)程度,影響全體人民利益,也會(huì)影響我們的經(jīng)濟(jì)生活、文化生活。)2.需要學(xué)習(xí)政治知識(shí) (5個(gè)有助于)3.需要參加政治實(shí)踐活動(dòng)。 (參加政治實(shí)踐的途徑;參加政治實(shí)踐的意義)(通過(guò)情景問(wèn)題,形成學(xué)生如何參與政治生活的方法;通過(guò)解決問(wèn)題,培養(yǎng)學(xué)生解決問(wèn)題的能力和發(fā)散思維的能力。)環(huán)節(jié)四 課堂小結(jié) 鞏固知識(shí)本節(jié)課我采用線索性的板書(shū),整個(gè)知識(shí)結(jié)構(gòu)一目了然,為了充分發(fā)揮學(xué)生在課堂的主體地位,我將課堂小結(jié)交由學(xué)生完成,請(qǐng)學(xué)生根據(jù)課堂學(xué)習(xí)的內(nèi)容,結(jié)合我的板書(shū)設(shè)計(jì)來(lái)進(jìn)行小結(jié),以此來(lái)幫助教師在第一時(shí)間掌握學(xué)生學(xué)習(xí)信息的反饋,同時(shí)培養(yǎng)學(xué)生歸納分析能力、概括能力。
2. let the Ss complete the forms paragraph by paragraph. Purpose here is to help Ss to get the habit of reading a passage as a whole, and pay attention to the organization of the text, as a result the Ss will fully understand the whole passage.3. ask Ss to retell the passage with the help of the key words in the form.Since the Ss in the class are in different levels, so I let them to fill in the blank to understand the meaning of the words and phrases better. ( That’s all for the while-reading. Now let’s move to the fifth step.)Step V: Post-reading (10mins) ---DiscussionIn this part students are asked to discuss in groups and list Wang Kun’s and Wang Wei’s attitudes about the trip. After that, Ss are encouraged to express their attitudes with the whole class. Collect their answers and don’t forget to praise them even if their answers may not be perfect.In this activity, discussion provides a vivid and active learning environment for Ss to communicate in English with newly learned language items. (Finally it comes to the homework.)StepⅥ: Homework (1min)1. Ss are required to read the text again after class and figure out the meaning of some complex sentences.2. Do the exercises on P19; This can help Ss to consolidate what they’ve learnt and make preparation for the next lessonPart4. Blackboard design.(說(shuō)板書(shū)設(shè)計(jì))On the top, there is the title of this lesson. On the left, there are main ideas for each paragraph. On the right, there are some new words and expressions.Unit 3 Travel journalJourney down the MekongMain idea of each para.:Para1: deciding to take a great bike trip along the Mekong river.Para2: Different attitudes between Wang kun and Wang wei.
Textbook: Senior English for China (Book 4), by Liu Daoyi Time Allotment: 1 period (40 minutes)Date: March 20, 2014Teaching aids: blackboard, Multi-media, Power Point, chalk I. Text Analysis (教材分析)This unit is about body language, and the text selected in the reading part demonstrates the difference and similarity of body language in many parts of the world. Through learning this passage, students are required to raise their awareness of using body language in different parts of the world. As body language is closely related to our daily life, it is easy to arouse students’ interest in learning this text. Reading skills and speaking training are designed around the text.II. Teaching Objectives (教學(xué)目標(biāo))By the end of the lesson, students will be able to:1. Language Skill Objective(語(yǔ)言技能目標(biāo)): develop reading ability (skimming and scanning)as well as speaking ability.2. Cultural Knowledge Objective(文化知識(shí)目標(biāo)): know about the cultural differences of using body language.3. Affective Objective(情感目標(biāo)): increase students’ awareness of using body language correctly in different cultures. III.Teaching Focuses and Difficulties(教學(xué)重點(diǎn)和難點(diǎn))1. Teaching Focuses(教學(xué)重點(diǎn)): the difference and similarity of body language in many parts of the world.2. Teaching Difficulties(教學(xué)難點(diǎn)): develop students’ reading abilities of skimming and scanning and ask the students to show their opinions with fluent English.
Step 7 Language points 1.Vocabulary (1) go through (2) set down (3) a series of (4) on purpose (5) in order to (6)at dusk (7)entirely (8)face to face 2.Important sentences (1)…I’ve grown so crazy about everything to do with nature. (2)There was a time when … (3)I stayed awake on purpose until … (4)It was the first time … that I’d seen the night … (5)It’s no pleasure looking through … Purpose: 1.Master the required vocabulary and sentence structures. 2.Use them freely. Step 8 Consolidation 1.Find out the topic sentences 2.Retell the text according to the topic sentences Purpose: I want to know if my students understand the text. Step 9 Discussion Imagine you have to go into hiding like Anne and her family, what would you miss most? Giveyour reasons. Purpose: Train Ss’ oral English ability. Step 10 Homework Write an article on Friends. Purpose: 1. Improve the Ss’ writing ability. 2 Train the Ss’ ability of self—teaching and looking up information by themselves. Part 5 Blackboard design(說(shuō)板書(shū)設(shè)計(jì))Unit 1 Friendship Reading Anne’s Best Friend 1.Main idea of each paragraph: Para. 1 Anne made her diary her best friend. Para .2 Anne wrote her feelings in her diary. Para .3 Anne missed nature. Para.4 Anne saw the night face to face Para.5 Anne wanted to experience nature outdoors. 2.Listening: Exx.1 P3 3.Discussion: Exx.3 P3 Purpose: 1.Make Ss familiar with the passage 2.Make the design inductive, instructive and artistic.
In this step, give students a few minutes to read the passage . While they are reading, I will write some key words of the text on the blackboard. Then ask students to retell the passage according to the key words.By retelling, students can improve their ability of language organization and have an overall understanding of the article.Step 4 Group discussionIn this step, students will be divided into groups of 4 to discussion the following question: What qualities make a great person?After their discussion, invite a few groups to make a report to the class.This group discussion can practice students’ oral English and cultivate their abilities of cooperation and communication.Step 5. HomeworkLet students write a short passage to introduce a great person he or she admires.The homework can consolidate the knowledge the students have learned and cultivate their writing ability. Part 6 Blackboard Design(板書(shū)設(shè)計(jì))That’s all my teaching procedures. Finally, I’d like to say sth about part 6 blackboard design. On the top is the title. On the left, there will be some new words and expressions. In the middle of the blackboard, I will write some useful sentence structures so that the students can know clearly what they’ve learned and then try to master the knowledge.OK. That’s all for my presentation. Thank you for your attention.
Purpose of my design:To ask the students to do these two tasks will make the Ss predict the story of this passage. As a result, it will deepen Ss’ memory of this story because they will have their own understanding of this story.Step 3. While-readingTask 1. (Individual work _____min)Skimming: ask students to skim the text and the main ideas of each paragraph in this passage. Please read it quickly and then match the sentences with the letters.Task 2. (Individual work _____min)Scanning: read the text quickly and decide the whether the following statements are true or false and give reasons.Task 3. (Pair work _____min)Listen to the tape and fill in the banks. Then read the paragraph with expression to your partner.Task4 (individual work min)Listen to the tape again and write down the main idea in one sentence.Purpose of my design: Enable students to understand the given material better by using different reading skills. And proper competition can arouse the Ss’ interest in English learning. “Task-based” teaching method is used here todevelop the Ss’ ability of communication and also their ability of co-operation will be well trainedStep 4. Post-readingTask 1. (Individual work, pair work, group work, class work; _____min)Discussion (group of 4):1. If you were Hippomenes, would you run against Atlanta?2. Do you think Hippomenes deserved to win the race? Why or why not?Step 5. HomeworkPlease read the story again carefully after class and imagine: What will happen during the race between Hippomenes and Atlanta? Who do you think will win the race? Do you think Atlanta would marry Hippomenes? Write an end for the story with thses questions.Purpose of my design: Homework is so important and necessary for to master the knowledge they learned after class. It will check whether the Ss achieve the teaching aims.Part 5 Blackboard design
In this class, I have 3 teaching aims, that is, knowledge aims, ability aims and emotion aims.1) Knowledge-Teach students new words and expressions, such as temporary, bleed,sprain choke, first aid, fall ill and so on.-Enable students to have a better understanding for some basic knowledge of first aid.2) Ability-Train students’ speaking, reading and writing abilities by different teaching activities, such as skimming, comprehending, team work, role play, retelling and writing.-Develop students’ reading strategy on how to move general idea to specific information.3) Emotion-Promote students’ awareness of giving first aid.- Cultivate students’ creativities.Then let’s come to my teaching methods and activities.III. Teaching methods and activities:To achieve different teaching aims, various kinds of teaching methods and activities will be adopted throughout this period, such as TBL (task-based learning), skimming, team work, brainstorm and others, which can offer students opportunities to fulfill tasks in which they can use language to achieve a specific outcome.IV. Teaching aids:Computer and blackboardV. Teaching important points:1) Make students have a clear mind for the structure of the text.2) Help students understand the theme of the text.VI. Teaching difficulties:1) So many new words may affect students’ understanding.2) How to get students to know about the functions of the skin and thecauses, characteristics and treatments for different degree burns,and the knowledge about giving first aid. VII. Blackboard design:
通過(guò)寫(xiě)文章梗概,培養(yǎng)學(xué)生綜合運(yùn)用語(yǔ)言的能力,學(xué)習(xí)用恰當(dāng)?shù)挠⒄Z(yǔ)描述科學(xué)家的故事。這是本課的教學(xué)難點(diǎn)。教師可以使用完形填空的方式來(lái)幫助學(xué)生整理語(yǔ)篇,從而來(lái)降低難度。本課的教學(xué)重點(diǎn)的突破方法是:在閱讀前,讓學(xué)生初步了解得出科學(xué)觀點(diǎn)所需要的基本程序,從而輕松而自然地導(dǎo)入文章的閱讀;在閱讀過(guò)程中,由易到難設(shè)計(jì)快速閱讀和精讀的問(wèn)題,層層推進(jìn)各種閱讀活動(dòng),讓學(xué)生對(duì)閱讀內(nèi)容從整體感知到細(xì)節(jié)理解,最后深層讀懂整篇文章,同時(shí)加強(qiáng)閱讀策略的指導(dǎo),讓每個(gè)學(xué)生都主動(dòng)參與課堂教學(xué)活動(dòng),最終達(dá)到提高閱讀能力的目的。Step 4 Post-readingGroup Activities四人小組共同合作,在老師的適當(dāng)指導(dǎo)下,就以下2個(gè)問(wèn)題展開(kāi)討論,讓學(xué)生就所知、所學(xué)、所感和所想融入話題,然后抽若干同學(xué)代表作小組發(fā)言。1. What do you think about John Snow, and what should we learn from him?2. Cholera was 19th century disease, which two diseases are similar to cholera today? Why?
Good afternoon, everyone. It’s my great pleasure to be here sharing my lesson with you. The content of my lesson is Senior English for China Book5 Unit 3 Life in the Future. I’ll be ready to begin this lesson from six parts: Analysis of the teaching material, Analysis of the students, Teaching aims and important and difficult points, Teaching methods and aids, Teaching procedures, and Blackboard design. First, let me talk about the teaching material.Part 1 Analysis of the Teaching Material:This unit is about what human beings’ life will be like in about one thousand years. By studying of this unit, we’ll Enable the students to know the changes in humans’ life and some new inventions bringing about the change and develop the interest in science. This lesson plays an important part in the English teaching in this unit. This is an important lesson in Book Five. From this lesson, it starts asking the Ss to grasp contents of each passage. Therefore, this lesson is in the important position of the teaching material. If the Ss can learn it well, it will be helpful to make the Ss learn the rest of this unit.Part 2 Analysis of the SsAs Senior2 Ss, they are at different levels of English fluency, some of them have lost interest in English. So during the lesson, I arrange a variety of activities to let all of them join in to attract their interest and let them be confident and taste the joy of success.
今天我們來(lái)介紹一下必修五第四單元的授課方式。這個(gè)單元的題目是Making the news。應(yīng)該是學(xué)生比較感興趣的話題,學(xué)生往往對(duì)新聞工作充滿好奇,所以我們可以利用這個(gè)機(jī)會(huì)多設(shè)計(jì)一些師生互動(dòng)和學(xué)生互動(dòng),來(lái)激發(fā)起學(xué)習(xí)的積極性,提高學(xué)習(xí)效率。同時(shí)我們可以利用這個(gè)單元不僅幫助學(xué)生掌握語(yǔ)言知識(shí),培養(yǎng)語(yǔ)言能力,同時(shí)讓其了解新聞工作的重要性,培養(yǎng)起社會(huì)智能感。這個(gè)單元分為六個(gè)課時(shí),它的教學(xué)目標(biāo)是這樣的:語(yǔ)言目標(biāo)是掌握詞匯表中的常用單詞和短語(yǔ),掌握倒裝句的一些基本用法。 技能目標(biāo)是能初步掌握約會(huì)的基本句型并在真實(shí)的場(chǎng)景下正確運(yùn)用。新聞報(bào)道類文章的寫(xiě)作技能。采訪的基本規(guī)范和溝通技能。情感目標(biāo)是對(duì)新聞報(bào)道的客觀性和真實(shí)性有更好的理解。對(duì)新聞?dòng)浾叩穆殬I(yè)有更深入的了解,并能體會(huì)其工作的重要性。下面我們來(lái)介紹一下第一課時(shí)的授課方式,第一課的教學(xué)目標(biāo)是這樣的第一課時(shí)的教學(xué)目標(biāo)語(yǔ)言目標(biāo):單詞:Occupation, journalist, editor, photographer, curious, personality, enthusiasm
分析過(guò)焦作市的地理概況和產(chǎn)業(yè)優(yōu)勢(shì)后,就需要針對(duì)由于資源枯竭所帶來(lái)的問(wèn)題提出合理化的建議。既然是談經(jīng)濟(jì)轉(zhuǎn)型,就應(yīng)該將話題的范圍明確在這一領(lǐng)域內(nèi)。通過(guò)材料3的相關(guān)內(nèi)容,我們了解到焦作市需要在產(chǎn)業(yè)結(jié)構(gòu)調(diào)整、培育新的優(yōu)勢(shì)產(chǎn)業(yè)、增強(qiáng)綜合競(jìng)爭(zhēng)力等三個(gè)整改方針上下功夫。因而引導(dǎo)學(xué)生針對(duì)優(yōu)勢(shì)與不足提出建議,以三個(gè)整改方針為基準(zhǔn),衡量建議的可行性是鍛煉學(xué)生解決此類問(wèn)題的有效途徑。在此我將教會(huì)學(xué)生的是解決問(wèn)題方法而非案例的內(nèi)容,正所謂“授之以魚(yú),不如授之以漁”。接下來(lái)針對(duì)學(xué)生的建議和教材資料分析所羅列的10點(diǎn)整改思路,由學(xué)生自由發(fā)言提出看法,通過(guò)教師的指導(dǎo)和學(xué)生的討論,進(jìn)而確定經(jīng)濟(jì)轉(zhuǎn)型建議的具體方案。最后注意將建議與產(chǎn)業(yè)優(yōu)勢(shì)相對(duì)照,看建議是否都是圍繞著產(chǎn)業(yè)優(yōu)勢(shì)而提出的,這樣做會(huì)加深學(xué)生的印象,通過(guò)建議和優(yōu)勢(shì)的對(duì)應(yīng)關(guān)系,將不難找出此類問(wèn)題的解題思路。
“深入探究,把握主旨”這一步則是解決教學(xué)的重點(diǎn)難點(diǎn),這里涉及到課文的深層意蘊(yùn),學(xué)生理解有難度,教師在通過(guò)問(wèn)題引領(lǐng)學(xué)生探討的基礎(chǔ)上,還要適時(shí)啟發(fā)、點(diǎn)撥,因?yàn)榻虒W(xué)時(shí)間有限,讓學(xué)生漫無(wú)邊際的討論,可能難以完成預(yù)定的教學(xué)任務(wù),會(huì)使教學(xué)過(guò)程不完整。至于本文的寫(xiě)作特點(diǎn)的教學(xué)視時(shí)間而定,有時(shí)間可以讓學(xué)生說(shuō)一說(shuō),沒(méi)有時(shí)間用小黑板出示一下,讓學(xué)生了解就行,如果時(shí)間不夠,甚至可以不講。第三階段是“延伸練習(xí),鞏固提高”。
(3)v. 給:提出;展現(xiàn),顯現(xiàn)present sb. with sth. ; present sth. to sb. 把. . 交給;頒發(fā);授予present sth. (for sth. )/present sth. to sb. e. g. Om his birthday, his friends presented him a collection of stamps. 在他生日時(shí),他的朋友們送給他一套郵票作為禮物。The sword was presented by the family to the museum. 這家人把寶劍捐贈(zèng)給了博物館。The committee will present the final report to Parliament in June. 委員會(huì)將在六月向議會(huì)提交最后的報(bào)告。You need to present yourself better. 你需要更善于展現(xiàn)自己。It is essential that we present a united front. 至關(guān)重要的是我們要表現(xiàn)得更加團(tuán)結(jié)。Step 4 ConsolidationT:Now that we have got a general idea of these words and phrases. Lets make up some sentences using them to master them. Suggested sentences:1. Your duties include typing letters and answering the telephone. 2. It is one of the greatest roles that she has played. 3. A large number of people have applied for the job. 4. The number of the panda is declining. 5. I'11 go there, even if I have to walk. 6. He came up to me to ask for a light. 7. The novel is about a family who can't communicate with each other. 8. He based his plan on interests of most people. 9. Why doesn't he make use of his singing talent?Step 5 Summary and homeworkT:Today we dealt with several new words and phrases. After class I hope that youcan read them again and again to keep them in mind. That's all for today. You aredismissed.
陸王心學(xué)與程朱理學(xué)相比有何異同?生 不同點(diǎn):在理的內(nèi)涵上不同,程朱理學(xué)認(rèn)為“理”是貫通于宇宙、人倫的客觀存在,是一種普遍的規(guī)律準(zhǔn)則;陸王心學(xué)認(rèn)為心即理,是“良知”,認(rèn)為人心便是世界萬(wàn)物的本原。方法上也有不同:前者向外追究,“格物致知”;后者向內(nèi)探求,“發(fā)明本心”以求理,克服私欲、回復(fù)良知。生 相同點(diǎn):都提出了一個(gè)宇宙、社會(huì)、人生遵循的“理”。師 對(duì)。程朱理學(xué)是客觀唯心主義,陽(yáng)明心學(xué)是主觀唯心主義。這兩者的分歧是理學(xué)范圍內(nèi)的分歧,其基本思想是一致的。師 宋明理學(xué)與漢唐以前的儒學(xué)比較,最大的特點(diǎn)在于批判地吸收了佛教哲學(xué)的思辨結(jié)構(gòu)和道教的宇宙生成論,將儒家的倫理學(xué)說(shuō)概括升華為哲學(xué)基本問(wèn)題。其實(shí)質(zhì)是把佛、道“養(yǎng)性”“修身”引向儒家的“齊家”“治國(guó)”“平天下”,對(duì)儒家的綱常道德給予哲學(xué)論證,使之神圣化、絕對(duì)化、普遍化,以便深入人心,做到人人遵而行之。
本節(jié)課是人教社物理必修1第三章第三節(jié)的內(nèi)容,編排在彈力之后。該節(jié)知識(shí)既是力學(xué)的基礎(chǔ),也是組成整個(gè)高中物理知識(shí)的一塊“基石”,所以這節(jié)內(nèi)容的教學(xué)如何引領(lǐng)學(xué)生自主積極地探究摩擦力產(chǎn)生的條件和影響因素,體驗(yàn)?zāi)Σ亮μ攸c(diǎn)規(guī)律的發(fā)生過(guò)程是本節(jié)課的重點(diǎn),應(yīng)高度重視本節(jié)教學(xué)過(guò)程;由于摩擦力問(wèn)題的復(fù)雜性,且在具體問(wèn)題中又表現(xiàn)出“動(dòng)中有靜,靜中有動(dòng)”,尤其靜摩擦在許多情形下似乎又是“若有若無(wú),方向不定”,因此,對(duì)于初學(xué)者也是有一定難度的。也正是由于教材內(nèi)容的上述特點(diǎn),本節(jié)課又易于激起學(xué)生的求知欲,易于培養(yǎng)學(xué)生的辯證觀點(diǎn),易于錘煉學(xué)生的物理素質(zhì)。要充分用好該節(jié)教材內(nèi)容,深入挖掘知識(shí)間的有機(jī)聯(lián)系,對(duì)學(xué)生開(kāi)展針對(duì)性的思維訓(xùn)練,進(jìn)而提高學(xué)生應(yīng)用物理知識(shí)解決實(shí)際問(wèn)題的能力和創(chuàng)新思維能力。高中物理《課標(biāo)》對(duì)該知識(shí)點(diǎn)的要求是,“通過(guò)實(shí)驗(yàn)認(rèn)識(shí)滑動(dòng)摩擦、靜摩擦的規(guī)律,能用動(dòng)摩擦因數(shù)計(jì)算摩擦力”。其中,對(duì)靜摩擦力規(guī)律的認(rèn)識(shí)應(yīng)該包括最大靜摩擦力。
(一)、復(fù)習(xí)提問(wèn)1、請(qǐng)說(shuō)出功的計(jì)算公式及功的單位2、我們用哪個(gè)物理量表示物體運(yùn)動(dòng)的快慢?(二)、創(chuàng)設(shè)情景,引入新課1、播放多媒體素材,用起重機(jī)和一個(gè)工人搬運(yùn)幾百塊磚比較哪一種方法好?圖中的情景說(shuō)明了什么問(wèn)題?(教師通過(guò)所設(shè)計(jì)的情景,將學(xué)生引入怎樣比較做功快慢,讓學(xué)生發(fā)表自己的看法,初步知道物體做功是有快慢之分的。)(三)、進(jìn)行新課1、比較做功快慢的方法播放多媒體素材并提出問(wèn)題:怎樣比較兩個(gè)人誰(shuí)做功快誰(shuí)做功慢?教師啟發(fā):以前學(xué)習(xí)過(guò)要比較兩物體運(yùn)動(dòng)的快慢,可以先確定路程再比較時(shí)間,也可以先確定時(shí)間再比較路程。在路程和時(shí)間都不同時(shí),通過(guò)計(jì)算速度比較兩物體運(yùn)動(dòng)的快慢。同理,要比較物體做功的快慢可采用什么方法?
探究一:高中階段功的含義是什么?投影:初中九年級(jí)《物理》105頁(yè)學(xué)生思考:①圖中物體的勢(shì)能、動(dòng)能分別如何變化?②物體能量的變化和做功是否存在關(guān)系?學(xué)生:分組討論,得出結(jié)論:如果物體的能量發(fā)生變化時(shí),說(shuō)明有力對(duì)物體做了功。教師:進(jìn)行點(diǎn)評(píng)和小結(jié)(設(shè)計(jì)意圖:對(duì)初中知識(shí)深化理論認(rèn)識(shí),并為以后功能關(guān)系的教學(xué)作準(zhǔn)備)探究二:力對(duì)物體做功的兩個(gè)要素是什么?情景再現(xiàn):找體重相對(duì)懸殊的兩位同學(xué),①A同學(xué)試圖抱起B(yǎng)同學(xué),但沒(méi)成功。②B同學(xué)抱起A同學(xué)在教室內(nèi)勻速走動(dòng)。學(xué)生思考:在①中,A是否對(duì)B做功?在②中,B是否對(duì)A做功?學(xué)生:分析得出做功的兩要素:物體受到力的作用,并且在力的方向上發(fā)生位移.教師:讓學(xué)生分別例舉生活中力對(duì)物體做功和不做功的例子,(設(shè)計(jì)意圖:讓學(xué)生親身參與課堂實(shí)驗(yàn),烘托課堂氣氛,相互協(xié)作增進(jìn)同學(xué)情誼)探究三:如果物體的位移不再力的方向上,那么力是否還對(duì)物體做功?