-
人教版高中英語必修1Earth quake說課稿
(4)Finally, I will ask the SS what this sentence mean：It is always calm before a storm.Purpose: attract the SS attention and bring them into discussionStep 2: Pre-reading 讀前Here, I will do the second question in pre-reading first. I will use the method of brainstorming to ask the SS what will happen before an earthquake; and list the phenomenon on the table. 2． Then I will show the SS the picture of abnormal phenomenon, at the same time, encourage the SS to describe.3、finally, I will summarize these phenomenon4、Do the first question in the pre-reading , Imaging your home begins to shake and you must leave it right away. You have time to take only one thing. What will you take? Why?Purpose: help the SS to get further understanding of the topic and stimulate their interests.Step3: While-reading 閱讀(1). Skimming Read the text quickly and catch the meaning of the first and second sentence of each paragraph. Predict the meaning of new words(2).scanning(找讀)A. Read the text again. Do the following question.1. When and where were the strange things happening?2. What are they?3. Why did the text say the world seemed to be at an end?4. How was the city destroyed after the quake?5. When did the second quake hit the city? What was the result of that?6. Who came to help Tangshan first? And how?B. Work in pairs to discuss the question.
人教版高中語文必修3《錦瑟》說課稿
三、教學(xué)目標根據(jù)《錦瑟》詩的地位作用以及學(xué)生的實際情況，還有在古詩詞教學(xué)方面課程標準的相關(guān)要求，現(xiàn)確定以下“三維教學(xué)目標”：（一）知識與技能目標：感受體悟古典詩歌的意境美，發(fā)揮合理的主觀能動性進行創(chuàng)新性的閱讀鑒賞，正確認識意象在詩歌意境中的重要作用。并在上述的基礎(chǔ)上提高鑒賞能力和審美情操。（二）過程與方法目標：《錦瑟》詩的講解采用“引導(dǎo)與自我生成”的方法，從老師的引導(dǎo)開始，以學(xué)生的研討交流再加之教師的總結(jié)結(jié)束。利用教師引導(dǎo)和師生互動刺激學(xué)生的領(lǐng)悟力，提高學(xué)生的認知水平與能力。（三）情感態(tài)度價值觀目標：培養(yǎng)學(xué)生在尊重傳統(tǒng)文化的基礎(chǔ)上熱愛祖國自己文化的態(tài)度，讓學(xué)生正確認識古典詩詞的精神美。最后在自我感悟中陶冶情操，明心啟智。
人教版新課標高中物理必修1用牛頓運動定律解決問題（一）教案2篇
（四）實例探究☆力和運動的關(guān)系1、一個物體放在光滑水平面上，初速為零，先對物體施加一向東的恒力F，歷時1秒，隨即把此力改變?yōu)橄蛭?，大小不變，歷時1秒鐘，接著又把此力改為向東，大小不變，歷時1秒鐘，如此反復(fù)只改變力的方向，共歷時1分鐘，在此1分鐘內(nèi)A．物體時而向東運動，時而向西運動，在1分鐘末靜止于初始位置之東B．物體時而向東運動，時而向西運動，在1分鐘末靜止于初始位置C．物體時而向東運動，時而向西運動，在1分鐘末繼續(xù)向東運動D．物體一直向東運動，從不向西運動，在1分鐘末靜止于初始位置之東☆牛頓運動定律的應(yīng)用2、用30N的水平外力F，拉一靜止放在光滑的水平面上質(zhì)量為20kg的物體，力F作用3秒后消失，則第5秒末物體的速度和加速度分別是A．v=7.5m／s，a=l.5m／s2B．v=4.5m／s，a=l.5m／s2C．v=4.5m／s，a=0D．v=7.5m／s，a=0
人教版高中地理必修3第一章第一節(jié)地理環(huán)境對區(qū)域發(fā)展的影響教案
教學(xué)重點：1．比較分析地理環(huán)境差異對區(qū)域發(fā)展的影響2．分析區(qū)域不同發(fā)展階段地理環(huán)境的影響教學(xué)難點：1．區(qū)域的特征2．以兩個區(qū)域為例，比較分析地理環(huán)境差異對區(qū)域發(fā)展的影響教具準備：有關(guān)掛圖等、自制圖表等教學(xué)方法：比較法、案例分析法、圖示法等教學(xué)過程：一、區(qū)域1．概念：區(qū)域是地球表面的空間單位，它是人們在地理差異的基礎(chǔ)上，按一定的指標和方法劃分出來的。2．特征：（1）區(qū)域具有一定的區(qū)位特征：不同的區(qū)域，自然環(huán)境有差異，人類活動也有差異。同一區(qū)域，區(qū)域內(nèi)部的特定性質(zhì)相對一致，如濕潤區(qū)的多年平均降水量都在800毫米以上。但自然環(huán)境對人類活動的影響隨著其他條件的變化而不同。（2）具有一定的面積、形狀和邊界。①有的區(qū)域的邊界是明 確的，如行政區(qū)；②有的區(qū)域的邊界具有過渡性質(zhì)，如干濕地區(qū)。
人教版高中政治必修1面對經(jīng)濟全球化說課稿
2、傳授新知與學(xué)生展示（35分鐘） 先由老師點出本課的知識點，它包括：(1)經(jīng)濟全球化深入發(fā)展：結(jié)合課本91-93頁理解經(jīng)濟全球化的含義；經(jīng)濟全球化的表現(xiàn)：生產(chǎn)全球化，貿(mào)易全球化，資本全球化；跨國公司是實現(xiàn)經(jīng)濟全球化的載體。（跨國公司的含義、目的、作用分別是什么）（2）經(jīng)濟全球化的影響: 經(jīng)濟全球化的實質(zhì)：以發(fā)達資本主義國家為主導(dǎo)的經(jīng)濟全球化；消極影響積極影響；如何應(yīng)對經(jīng)濟全球化。講完了知識點，接著回歸圖片和書本的材料，給學(xué)生留下三個問題進行小組討論：A ：談?wù)勀愀惺艿降慕?jīng)濟全球化B :怎樣理解經(jīng)濟全球化是一把“雙刃劍”C:假如你是一位企業(yè)經(jīng)營者，面對經(jīng)濟全球化趨勢，你會怎么做？先完成討論的小組可舉手示意老師給予檢查，老師根據(jù)需要抽查同學(xué)到講臺進行展示討論的結(jié)果，并對表現(xiàn)突出的小組進行當堂獎勵。
人教版高中歷史必修3啟蒙運動說課稿
教材地位本課具有承上啟下的作用，前承文藝復(fù)興，后啟資產(chǎn)階級革命時代的到來，啟蒙運動為資本主義社會構(gòu)建了一套政治藍圖，具有前瞻性，是近代第二次思想解放運動。因此，本節(jié)內(nèi)容在整個教材中有著很重要的地位。教學(xué)目標1、知識目標：（1）幫助學(xué)生了解啟蒙運動的性質(zhì)、內(nèi)容和主要啟蒙 思想家及其主張。（2）理解啟蒙運動興起的背景、影響。2、能力目標：（1）在討論和探究過程中訓(xùn)練學(xué)生的科學(xué)思維方法和自主學(xué)習(xí)的能力和掌握解題的方法。（2）通過指導(dǎo)學(xué)生閱讀啟蒙思想家的言論資料，培養(yǎng)學(xué)生對歷史資料的理解和歸納能力。3、情感價值目標：（1）培養(yǎng)人文意識，強化法治觀念。（2）培養(yǎng)學(xué)生的團結(jié)協(xié)作精神和競爭意識。教學(xué)重點、難點(1)教學(xué)重點：啟蒙思想家的主張及啟蒙運動的影響。
人教版高中語文必修2《采薇》教案2篇
這兩章是對戰(zhàn)爭場面的描寫。寫的是戰(zhàn)車、戰(zhàn)馬、象弭、魚服以及士兵的勞累奔波、饑渴難當，通過這些具體生動的細節(jié)描寫來展現(xiàn)戰(zhàn)爭生活的圖景。而沒有寫戰(zhàn)場上的刀光劍影、廝打拼殺，但戰(zhàn)爭的殘酷已可想見。4“昔我往矣，楊柳依依。今我來思，雨雪霏霏”被視為情景交融的佳句。清人王夫之在論《詩經(jīng)·小雅·采薇》這兩句時說：“以樂景寫哀，以哀景寫樂，一倍增其哀樂?！闭?wù)勀愕目捶?。一以往昔之虛襯眼前之實，以出征之樂襯內(nèi)心之思親之悲痛；二“楊柳依依”與“雨雪霏霏”對比，突出不勝今昔之感；三大雪交加，饑渴難當，情境實悲，以哀景寫哀情。四、交流延伸1寫一首詩或一段文字表達你對“鄉(xiāng)愁”的新的體驗。在全班交流。2課后搜集更多的表現(xiàn)鄉(xiāng)情的詩歌散文作品，將你最感動的一篇拿到班上與同學(xué)分享感受。
人教版高中語文必修2《涉江采芙蓉》教案2篇
三、想象畫面，把握意境1.指導(dǎo)想象學(xué)習(xí)陶淵明的《歸園田居》我們腦海中自然會出現(xiàn)一幅幅的畫面，比如他歸家后的生活場景，我們會想象“榆柳”是如何遮蔽房屋的，而“桃李”又是如何摘種在房前的。我們會想象村落是如何在薄霧中若隱若現(xiàn)的，想象炊煙是如何裊裊升起的?！渡娼绍饺亍芬辉娭挥?句話，更需要我們展開想象，去構(gòu)畫場景，這樣才能深入詩歌，體會到詩歌的味道。2.學(xué)生想象要求學(xué)生閉目想象1分鐘。3.學(xué)生展示想象結(jié)果（抽三四個學(xué)生回答即可）4.老師指導(dǎo)糾正學(xué)生想象不合理之處。要注意的地方：“江”可能學(xué)生會想象成小溪流、小池塘?！疤m澤”可能學(xué)生理解成“湖泊”。注意字詞“還顧”“漫浩浩”中隱含的情感，注意“離居”中流露的愁怨。5.時間允許的話，老師讀自己的下水作文。
人教版高中語文必修2《演講》教案2篇
一個世紀前，一位了不起的美國人簽署了奴隸解放宣言，而我們今天就站在他的塑像下面。對于千千萬萬身受不公正待遇之苦的黑奴來說，這份劃時代的文件，是一座光芒萬丈的希望燈塔，是結(jié)束他們被束縛之漫漫長夜的快樂黎明。我有一個夢，有朝一日在喬治亞州的丘陵地帶，奴隸的后代與奴隸主的后代，將能夠兄弟般地相處。我有一個夢，有朝一日甚至密西西比州，這個充滿不平與壓迫的州，將轉(zhuǎn)化成一片自由與公正的綠洲。我有一個夢，我的四個孩子，有朝一日將可以生活在這樣一個國度里：在此人們不是根據(jù)他們的膚色，而是根據(jù)他們的品行來衡量他們。我今天有一個夢！我有一個夢，有朝一日在阿拉巴馬州，盡管目前有許多惡毒的種族主義者，盡管州長叫嚷著要與聯(lián)邦政府對抗，有朝一日在阿拉巴馬州，黑人孩子與白人孩子將會像兄弟姊妹那樣親密無間。
人教版高中語文必修2《孔雀東南飛并序》教案2篇
讓學(xué)生仔細聆聽美妙的音樂，合作討論，加深理解。（1）本詩文中的“蘭芝被遣”和“蘭芝抗婚”的情節(jié)，可與樂曲展開部第一階段“逼嫁抗婚”對比閱讀。文中的劉蘭芝是在封建禮教的壓迫下被遣歸及被迫“改嫁”，劉蘭芝與祝英臺一樣都進行了抗爭。樂曲中的樂器奏出了具有威脅力的封建勢力的主題，代表著封建勢力的兇暴殘酷，同時敘述了祝英臺的悲痛和不安心情，表現(xiàn)了控訴、抗爭的感情。（2）本詩文中的“夫妻誓別”的情節(jié)，可與樂曲呈示部中的結(jié)束部“長亭惜別”對比閱讀。文中劉蘭芝與焦仲卿的誓別。二人分手之際，依依不舍，“舉手長勞勞，二情同依依”。樂曲中梁祝分別時依依不舍又充滿悲傷，音調(diào)抒情徐緩。讓學(xué)生在徐緩的音樂中去感受劉蘭芝與焦仲卿生離死別的痛苦。
人教版高中語文必修2《離騷》教案2篇
四、品味詩歌藝術(shù)1、詩人是如何表現(xiàn)其品質(zhì)的？運用了什么修辭手法？產(chǎn)生了怎樣的表達效果？明確：詩句“扈江離與辟芷兮，紉秋蘭以為佩”很好地體現(xiàn)了詩人光輝俊潔的人格。用“江離”“辟芷”“秋蘭”三種香草來裝飾自己，比喻自己，極其生動形象地表現(xiàn)了詩人自己美好的精神世界，使詩歌充滿了浪漫主義氣息。2、《離騷》中作者常以“香草”、“美物”來比喻自己、賢士和君王，并表達政治理想，這是《離騷》的一大藝術(shù)特色，這種方法叫做“移情法”，即不直接說出自己想說的話，而是把它寄寓于某一物上，也就是“移情于物”，這種方法在古典詩詞中廣泛運用，在政治不清明的時代，借用“移情”，可言難言之語，抒難抒之情。請找出相關(guān)的詩句，說說詩人是怎樣運用這些比喻來表達政治理想的。
人教版高中語文必修2《囚綠記》教案2篇
教學(xué)設(shè)想：本節(jié)課的主題是“生命之綠，璞玉心靈”，用圈點批注法解讀愛綠的感情，讓學(xué)生在批注中明確“綠”的象征意義，而不只是結(jié)論的傳遞。同時借助于閱讀、感受和理解把握作者對綠的認識是不斷升華的，由一般對生命希望之綠的喜愛，到與綠交往后被它的不畏強暴，永遠向陽的精神所折服，最后在特定的時代背景下綠在作者的心目中已經(jīng)成了我們民族不屈精神的象征。讓學(xué)生評中求解，評中悟情，評中明理，評中品味。教學(xué)進程:一、導(dǎo)語上節(jié)課我們學(xué)習(xí)了朱自清的《綠》，初步了解了讀書動筆的基本方法，這節(jié)課我們繼續(xù)用圈點批注的方法來學(xué)習(xí)陸蠡的散文《囚綠記》。二、釋題師：看標題，囚綠之“綠”在文中具體指什么？（一株常春藤）“囚”就是囚禁的意思，那題目就是記述囚禁綠色常春藤的經(jīng)過。三、圈點、把握情節(jié)作者為什么要囚綠呢？文中除了寫“囚綠”之外，還寫了哪些有關(guān)綠的意念和行動？帶著這樣的質(zhì)疑用自己喜歡的方式朗讀課文，請同學(xué)們?nèi)c出疑難字詞，或結(jié)合書下注釋，或同學(xué)合作解決，解決不了的，可提出來我們共同解決。標注段落節(jié)次。勾畫出表現(xiàn)作者對綠意念和行動的句子。
人教版高中語文必修2《巴黎圣母院》教案2篇
【教學(xué)設(shè)想】一、選題設(shè)想《巴黎圣母院》是雨果的代表作，無論從思想內(nèi)容還是藝術(shù)風(fēng)格都有明顯的浪漫主義特征：奇異曲折、扣人心弦的故事情節(jié)；妙趣橫生、別出心裁的奇遇巧合；強烈鮮明的美丑、善惡對比；豐富生動、珠璣迸發(fā)、富有哲理意味的語言。通過導(dǎo)讀，來消除學(xué)生對外國名著的畏難情緒，增加學(xué)生課外閱讀的興趣和信心；讓學(xué)生整體把握作品，窺一斑而識全豹，讓學(xué)生高屋建瓴，了解其旨意，以極為精確而又充滿意蘊的文字，對名著的概述及精要部分做了介紹；引導(dǎo)學(xué)生自主探究，交流合作，培養(yǎng)學(xué)生的獨立思考的學(xué)習(xí)慣，指點進行名著閱讀的門徑。作為導(dǎo)讀課，教師應(yīng)注意不可“越位”，在學(xué)生學(xué)習(xí)的過程中，教師的“導(dǎo)”固然重要，學(xué)生的“讀”更不可或缺，應(yīng)避免以“導(dǎo)讀”來代替名著閱讀。因此，《巴黎圣母院》的教學(xué)定位為基于課內(nèi)，面向課外，以求達到以學(xué)帶讀，以讀促學(xué)的目的。
人教版高中語文必修2《短歌行》教案2篇
教學(xué)過程：一、導(dǎo)語毛澤東在《沁園春雪》俯視封建君王“惜秦皇漢武。。。只識彎弓射大雕?！钡绻麣v史上只有一個人可以與他相提并論，這個人只能是魏武帝曹操。“滾滾長江東逝水，浪花淘盡英雄。是非成敗轉(zhuǎn)頭空，青山依舊在，幾度夕陽紅?！保ā度龂萘x》卷首詞）在歷史的大浪淘沙中，有多少英雄能夠經(jīng)得起歷史的千淘萬漉而流芳百世呢？曹操應(yīng)該是三國時代留下了濃重一筆的人物。老師總結(jié)，并啟發(fā)他們?nèi)ヂ?lián)系:我們學(xué)過他的《觀滄?！贰皷|臨碣石,以觀滄海…”還有《龜雖壽》“神龜雖壽，猷有竟時。老驥伏櫪，志在千里；烈士暮年，壯心不已。”《青梅煮灑論英雄》中曾和他見過，《三國演義》電視劇播出后，大家和他也就頻頻見面了。《三國演義》第48回“宴長江曹操賦詩”中，赤壁之戰(zhàn)前夕，曹操和眾部將一起狂飲，他四顧空闊，心中大喜，與諸將講述自己希望收服江南的雄心壯志。
新人教版高中英語必修2Unit 2 Wildlife Protection-Reading for Writing教案二
This lesson aims at making a poster about protecting wildlife after reading some posters. During reading students are guided to understand the content and try to summarize the posters with one sentence. Then students are guided to try to make a poster about protecting wildlife.1. Read the two posters and try to understand the summary sentences.2. Look at the two posters and try to understand what emotions they express.3. Try to summarize the features of posters4. Try to make a poster about wildlife.1. Look at the two posters and try to understand what emotions they express.2. Try to summarize the features of posters3. Try to make a poster about wildlife.Step 1 Lead inLook at the the posters on the textbook and ask:Which emotions do the posters communicate ?Step 2 Read the poster and answer the questions.1. What do you think of the animals in the poster on the left ?I think it is frightening and ugly.2. Why do we should protect the ugly animals ?All species--the good, the bad, and the ugly-- should be treated equally.The world needs all kinds--without variety, our planet cannot survive.3. Why are billions of trees being cut down every year ?To make paper for humans.4. What result will be lead to after the trees are cut down ?A lost of animal homes are being destroyed./The habitat of wildlife is being destroyed.Step 3 Find the feature of posters1. What does each poster use to stir up emotions ?On the left, it makes us a little frightened and it looks a little ugly, but it can activate our curiosity--What is it? And What is wrong with it?On the right, it makes us feel a little sad and want to protect them.
新人教版高中英語必修2Unit 2 Wildlife Protection-Discovering Useful Structure教案二
2．表示現(xiàn)階段正在進行的被動動作(該動作在說話的瞬間未必正在進行)。Many interesting experiments are being carried out these days.(說話時，并不一定正在進行)3．表示一種經(jīng)常性的被動行為，常和always，constantly 等表示頻度的副詞連用，這種用法常常帶有贊揚或厭惡的感情色彩。He is always being praised by the leader.4．表示按計劃或安排主語將要承受謂語動詞所表示的動作(僅限于少數(shù)及物動詞)。A party is being held tonight.Step 4 Special cases1.像take care of, look after, talk about, think of等動詞與介詞構(gòu)成的短語用于現(xiàn)在進行時的被動語態(tài)時, 其中的介詞不可省略。The ways to stop illegally hunting are being talked about. 2．可與部分情態(tài)動詞連用，表示對正在發(fā)生的事情的推測。She may be being punished by her mother.3．有時可表示按計劃或安排將要進行的一個被動動作。A celebration is being held this weekend for his success.4．某些表示“狀態(tài)、心理活動、存在”等的動詞，如have，want，need，love，一般不用現(xiàn)在進行時的被動語態(tài)，而常用一般現(xiàn)在時的被動語態(tài)。With the population increasing，more land is needed.5．“be＋under/in＋n.”可表示現(xiàn)在進行時的被動意義。My computer is under repair.＝My computer is being repaired.
新人教版高中英語必修2Unit 2 Wildlife Protection-Listening &Speaking＆Talking教案
Listening and Speaking introduces the topic of “how to save endangered wildlife and help wildlife in their neighborhood.” Due to the continuous deterioration of the living environment, a large number of wild animals are always facing the threat of endangered or extinction. Listening and speaking period enables students to understand the fact and reason why wild species are disappearing from the earth at an amazing speed, and realize that human beings ought to enhance the awareness of protecting wild species as soon as possible.Listening and Talking introduces the theme of " how to help wildlife in Ss’ neighborhood.". Now there are many volunteers who spontaneously protect wild animals, carry out various activities according to local conditions, and contribute their own strength to local animal protection with practical actions. Middle school students are also enthusiastic participants. They organize activities in their spare time, and take this opportunity to make friends, broaden their horizons, cultivate team spirit and communication skills. This section describes a bird watching activity organized by several middle school students of Bird watching Club. It aims to stimulate students' interest, improve their understanding of bird watching activities, and use the language structure of “being used for; in order to, so as to, to, so that, in order that ” to express the purpose for communication and discussion.1. Guide students to understand the content of listening texts in terms of using visuals to predict content.2. Cultivate students' ability to guess the meaning of words in listening; discuss with their peers how to save endangered wildlife and help wildlife in their neighborhood.3. Instruct students to use functional sentences of the dialogue such as “I am concerned about…” “what do you know about the endangered animals in…" and so on to talk about one of the endangered animals.
新人教版高中英語必修2Unit 2 Wildlife Protection-Listening and Speaking教案
This lesson is about wildlife protection. The listening and speaking is about “How to protect endangered wildlife ?” Faced with the facts and numbers of wildlife loss, people begin to detect the reasons, then people such as the celebrities (Prince William and Yao Ming) are calling on to protect them. So students are guided to enhance the awareness of protecting wildlife and try to take part in some volunteer activities of protecting wildlife.1. Predict the content by using visuals. 2. Learn to use the sentences such as “I’m concerned about.... But now they are in danger. I want to know the reasons/why./ What can we do to protect them ?3. Learn from the stars like Prince William and Yao Ming and enhance the awareness of protecting wildlife.4. Guide students to try to put forward the solutions to the problems of wildlife protection and then discuss them with partners and present the results of discussion.5. Master the pronunciation of stressed syllables.1. Learn from the stars like Prince William and Yao Ming and enhance the awareness of protecting wildlife.2. Guide students to try to put forward the solutions to the problems of wildlife protection and then discuss them with partners and present the results of discussion.3. Learn to use the sentences such as “I’m concerned about.... But now they are in danger. I want to know the reasons/why./ What can we do to protect them ?4. Master the pronunciation of stressed syllables.Part A Listening and Speaking--- How to save endangered wildlifeStep 1 Lead in1. Point at the pictures on P14 and ask Q1: What message do these posters share?
新人教版高中英語必修2Unit 2 Wildlife Protection-Reading and Thinking教案二
The theme of this unit is human and nature, focusing on the theme of wildlife protection. Nature is a complex ecosystem, in which there are delicate balance between animals and plants. Because of the role of the food chain, the extinction of one species will produce influence, causing a series of chain reaction. Large scale extinction of species will have a serious and even irreversible impact on the ecosystem, resulting in immeasurable losses. Therefore, it is of great significance to protect wild species. To protect wild species is to protect human beings themselves. The motto of this unit is "when the buying stops, the killing can too,” which is a public service advertising slogan to protect wildlife. It tells people that every rhinoceros horn, every fur, every bowl of shark fin soup, every Ivory product, and every tiger bone product, etc. consumed by human beings, are innocent wild animals slaughtered behind them. The mission of wild aid is to ban illegal trade in endangered wildlife and mitigate climate change. It aims to educate the public to reduce the consumption demand for endangered wildlife products through public publicity and improve the awareness of environmental protection.1. Improve the awareness of wildlife protection by acquiring the knowledge of wildlife protection.2. Focus on environmental protection and protection of all lives.3. Analysis of the living environment of wild animals with appropriate thinking mode.4. Skillfully use the vocabulary and grammar knowledge of this unit to cultivate self-study ability according to the unit content5. Develop cooperative learning ability through discussion and other ways1. Enable the Ss to talk about the current situation of wild animals.2. Guide the Ss to summarize the main idea of each paragraph as well as the main idea of the text.
人教版新課標高中物理必修2功率教案2篇
1．用CAI課件模擬汽車的啟動過程。師生共同討論：①如果作用在物體上的力為恒力，且物體以勻速運動，則力對物體做功的功率保持不變。此情況下，任意一段時間內(nèi)的平均功率與任一瞬時的瞬時功率都是相同的。②很多動力機器通常有一個額定功率，且通常使其在額定功率狀態(tài)工作（如汽車），根據(jù)P=FV可知：當路面阻力較小時，牽引力也小，速度大，即汽車可以跑得快些；當路面阻力較大，或爬坡時，需要比較大的牽引力，速度必須小。這就是爬坡時汽車換低速擋的道理。③如果動力機器在實際功率小于額定功率的條件下工作，例如汽車剛剛起動后的一段時間內(nèi)，速度逐漸增大過程中，牽引力仍可增大，即F和v可以同時增大，但是這一情況應(yīng)以二者乘積等于額定功率為限度，即當實際功率大于額定功率以后，這種情況不可能實現(xiàn)。
