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新人教版高中英語必修2Unit 3 The Internet-Listening &Speaking＆Talking教案一
Listening and Speaking introduces the topic of “ask about online habits”. Many middle school students have been surfing the Internet for many years, but what they do with the Internet and how much time they spend every day may not be very clear to themselves, nor to other students. This section allows students to investigate their peers' Internet use, which is conducive to their mutual understanding and understanding of the Internet. It can also help them reflect on their own online behavior, learn from other people's good online habits, and get rid of their bad online behavior.The listening text of this section is an investigation interview. The investigators interview specific groups with the same questions to obtain information, so as to understand their views, practices or attitudes on this issue. There are two specific questions: “how much time do you spend online every day? What do you usually do online?”. The answers of the three respondents provide rich and different information, and achieve the purpose of the investigators. The oral discourse structure of survey interviews generally includes greeting and explaining the purpose of the interview, presenting the interview questions and the respondents' answers. Listening and Talking introduces the theme of “choosing the right application ". Listening text is a conversation between Laura and Xiao Bo. In this part of listening, “oink”； “piggy bank” may cause the students' hearing comprehension limitation. Oink refers to sound word and pig's sound. So, add some oink to my piggy bank is often used to describe "making a little money".1. Guide students to understand the content of listening texts in terms of listening for definitions.2. Cultivate students' ability to define words and understand an investigation interview.
新人教版高中英語必修2Unit 3 The Internet-Reading and Thinking教案一
Paragraph 3. Jan decided to start an IT club to teach old people how to use computers and the Internet. Paragraph 4. Jan has started taking online classes to learn more about how to use the Internet to make society better. Paragraph 5. Jan’s life has been greatly improved by the Internet. Step 5: Critical thinking:(1)How do you arrange your time spent on study and the Internet? Is it reasonable? I usually surf the Internet using my mobile phone for only an hour after class, and it is reasonable for me.(2)What are your online activities? Are they safe? I chat with my friends, read news and play games. I never give away my private information so I think they are safe.Step 4: summary Much has been written about the wonders of the World Wide Web. There are countless articles (1)______(tell) us how the Internet has made our lives more convenient. But the Internet has done a lot (2)_____(much) for people than simply make life more convenient. People’s lives (3) _________________(change) by online communities and social networks so far. Take Jan for example, who developed a serious illness that made her (4)_____(stick) at home with only her computer to keep (5)___(she) company. She joined an online group (6)______ she could share problems, support and advice with others. She considered the ability to remove the distance between people as one of the greatest (7)_______(benefit). She was so inspired (8)____ she started an IT club in which many people have been helped. She has started to learn more about how to use the Internet to make society better. Her next goal is to start a charity website to raise money (9)___ children in poor countries. Jan’s life has been (10)______(great) improved by the Internet. Step 5 Homework:Review what we have learned and find out the key language points in the text.
人教版高中政治必修3感受文化影響教案
世界觀、人生觀、價值觀是人們文化素養(yǎng)的核心和標(biāo)志。一個人的世界觀、人生觀、價值觀是在長期的生活和學(xué)習(xí)過程中形成的，是各種文化因素交互影響的結(jié)果。世界觀、人生觀、價值觀一經(jīng)形成，就具有確定的方向性，對人的綜合素質(zhì)和終身發(fā)展產(chǎn)生深遠(yuǎn)而持久的影響?！笳n堂探究：(1)你能補充一兩個定居海外的華裔在生活方式和習(xí)俗方面仍然表現(xiàn)出受我們民族文化影響的事例嗎?(2)能否談?wù)勀汩喿x這段話時的感悟，并用自己的理解說明文化對人的影響力?◇探究提示：(1)啟發(fā)同學(xué)們搜集材料，了解歷史上或現(xiàn)實生活中海外華僑的生活方式受中華民族文化影響的具體事例。(2)通過閱讀這段話，可以感受到，一段豐富的人生經(jīng)歷、一份令人心動的情感、一種遠(yuǎn)大的理想、一種催人奮進(jìn)的力量，會深深地影響著人的發(fā)展。
人教版高中語文必修3《宇宙的邊疆》教案
一、內(nèi)容與解析從古代運用天文方法確定耕作時間，到現(xiàn)代對宇宙形成演變的種種假設(shè)，對宇宙的探索，已經(jīng)成為人類生活的一部分。宇宙從何而來，向何而去，人類從何而來，向何而去，這些基本問題不僅具有科學(xué)意義，而且具有哲學(xué)的意味。以前教材中沒有出現(xiàn)過解說詞，但是在日常生活中，我們經(jīng)常接觸到各類解說詞，可以讓學(xué)生聯(lián)系實際，了解解說詞的特點；也可以找來其他科學(xué)電視片，結(jié)合視覺畫面，讓學(xué)生全面地感受解說詞的特點。二、教學(xué)目標(biāo)及解析（一）教學(xué)目標(biāo)1．引導(dǎo)學(xué)生聯(lián)系實際，了解解說詞的特點。2．引導(dǎo)學(xué)生了解一些有關(guān)宇宙的基礎(chǔ)知識。3．引導(dǎo)學(xué)生借助文中精辟的議論和熱烈的情感抒發(fā)，了解作者對宇宙和人類的思考，并引發(fā)自己的思考。
人教版高中語文必修3《祝?！方贪?篇
小結(jié)人們對待祥林嫂這個“嫁而再寡”的不幸女人態(tài)度：①、魯四老爺?shù)膽B(tài)度：不讓她干祭祀的活（71、73、75、108通過四嬸先后三喊“你放著罷”，殺人不見血地葬送了祥林嫂的性命。而其中尤以最后一次對其打擊最大）。魯四老爺站在頑固維護(hù)封建宗法制度的立場上，從精神上殘酷地虐殺她。他暗暗地告誡四嬸的那段話，就是置祥林嫂于死地而又不露一絲血痕的軟刀子。②、魯四嬸的態(tài)度：魯四嬸是“大戶人家的太太”，頭一次留祥林嫂是看她能干，祥林嫂被婆家綁架走以后，她害怕給自己家惹麻煩。之后她惦念祥林嫂不是因為關(guān)心她的命運，而是自己的傭人都沒有祥林嫂那樣可心。以后祥林嫂再來，她“起初還躊躕”，后來倒是真心憐憫祥林嫂，留下她。但是祥林嫂不像過去那樣靈活能干了，四嬸開始“不滿”，進(jìn)而“警告”，最后把祥林嫂趕出家門。可以說，四嬸只是把祥林嫂當(dāng)成一件工具罷了，沒有把她當(dāng)人來看。
人教版高中歷史必修3啟蒙運動教案2篇
教學(xué)目標(biāo)：1、知識與能力：（1）識記：理性、啟蒙運動；伏爾泰、孟德斯鳩、盧梭等偉大的啟蒙思想家及其主張；康德及啟蒙運動的影響；（2）理解啟蒙運動興起的背景，分析啟蒙思想的巨大影響；（3）認(rèn)識上層建筑對社會發(fā)展的巨大反作用。2、過程與方法：（1）指導(dǎo)學(xué)生用表格法掌握啟蒙運動主要代表人物及其思想主張；（2）運用比較法加深對啟蒙思想家觀點共性和個性的認(rèn)識。（3）運用比較法對比文藝復(fù)興和啟蒙運動的異同，說明啟蒙運動對人文主義思想的發(fā)展。3、情感態(tài)度與價值觀：（1）通過本課的學(xué)習(xí)，讓學(xué)生認(rèn)識到“一定的文化是一定社會的政治和經(jīng)濟在觀念上和形態(tài)上的反映”；（2）學(xué)習(xí)啟蒙思想家追求真理的精神，培養(yǎng)學(xué)生遠(yuǎn)大的理想與抱負(fù)；（3）通過法國啟蒙思想產(chǎn)生的巨大影響的分析，使學(xué)生認(rèn)識意識形態(tài)對社會發(fā)展所起的重大作用，從而提高學(xué)習(xí)理論的自覺性。
人教版高中政治必修3世界文化的多樣性教案
五、課后反思課后組織學(xué)生討論對本課的感受，同學(xué)們都非常樂意采取這種上課方式，既可以通過資料的搜集、整理提高自身信息采集的能力，也能夠提高自己學(xué)習(xí)積極性，變枯燥為生動。本人在教學(xué)中也深深地感到：一方面，充分發(fā)揮學(xué)生的主體作用，有利于啟發(fā)同學(xué)的思維，培養(yǎng)自主思考的能力。而充分利用網(wǎng)絡(luò)的教學(xué)功能，將現(xiàn)代信息技術(shù)和學(xué)科教學(xué)很好地結(jié)合了起來。只有調(diào)動全體同學(xué)的積極性、主動性、創(chuàng)造性，我們的教學(xué)才能有生命力；另一方面，光有學(xué)生的活動也不行，雖然學(xué)生能夠積極投入地利用互聯(lián)網(wǎng)搜集并動手制作課件，在課堂交流中能很好地進(jìn)行發(fā)散思維和創(chuàng)造性思維，但其集中思維和抽象性思維還存在一定的缺陷，主要體現(xiàn)在對搜集的材料的取舍是以及對知識點的歸納和深化方面，所以在充分發(fā)揮學(xué)生的主體作用的同時應(yīng)該也必須重視教師主導(dǎo)作用的發(fā)揮，引導(dǎo)學(xué)生由形象到抽象、由發(fā)散到集中、由演繹到歸納的思維能力的逐步提高。
人教版高中政治必修3我們的民族精神教案
2.弘揚和培育中華民族精神，是提高全民族綜合素質(zhì)的必然要求Why：（1）一個民族的發(fā)展也取決于民族的綜合素質(zhì)（2）民族精神是民族綜合素質(zhì)的有機組成和集中體現(xiàn)（3）高昂奮進(jìn)的民族精神能產(chǎn)生巨大的力量，發(fā)揮不可估量的作用學(xué)生活動：你能舉出生活中民族素質(zhì)有待提高的事例嗎？試著分析一下如何解決。舉例：南京的市罵、中國公民在國外的隨地吐痰、亂扔亂丟現(xiàn)象。3.弘揚和培育中華民族精神，是不斷增強我國國際競爭力的要求Why：（1）文化在綜合國力的競爭中的地位和作用越來越突出（2）民族精神作為中華文化的精髓，具有凝聚和動員民族力量、展示民族形象的重要功能，已成為表明綜合國力強弱的至關(guān)重要的因素之一學(xué)生活動：“憶一憶”文化在綜合國力競爭中具有怎樣的意義？（P11、P22，關(guān)鍵詞：精神武器、深深熔鑄、重要標(biāo)志、智力支持、方向保證、精神動力）
人教版高中政治必修3文化與經(jīng)濟、政治教案
另一方面，文化素質(zhì)影響公民政治權(quán)利的行使。隨著民主和法制建設(shè)的發(fā)展，人們?yōu)榱藚⑴c政治生活，需要更高的文化素養(yǎng)。文化水平提高了，人們受到的教育、接受的信息就越多，活動的領(lǐng)域就越廣，民主法制和權(quán)利意識就越強，這些都會影響人們的民主素質(zhì)和民主水平，使人們更好地進(jìn)行政治參與，行使民主權(quán)利。(2)文化與國際政治相互交融，成為當(dāng)代國際政治斗爭的重要內(nèi)容。隨著世界多極化的發(fā)展，奉行霸權(quán)主義的國家，借助文化滲透的方式，竭力推銷自己的價值觀念，企圖削弱和取代別國的民族文化，以推行強權(quán)政治。這使世界范圍內(nèi)反對文化霸權(quán)主義的斗爭，成為當(dāng)代國際政治斗爭的重要內(nèi)容。文化已經(jīng)成為進(jìn)行政治斗爭、國際斗爭的重要形式之一。對文化市場的爭奪不僅僅是爭奪票房價值、爭奪經(jīng)濟效益，更主要的是對受眾對象的爭奪，對受眾注意力這種特殊的稀缺資源的占有，以及在此基礎(chǔ)上對輿論的控制與引導(dǎo)。因此，失去文化市場就意味著失去政治優(yōu)勢，意味著政治影響力的邊緣化乃至萎縮或喪失。這一點，從目前世界正在進(jìn)行的空前規(guī)模的“文化戰(zhàn)爭”，可以看得非常清楚。
新人教版高中英語必修2Unit 3 The Internet-Discovering Useful Structure教案一
This unit is about the Internet, which has a great influence to our humans and our lives. During the Listening & Speaking & Talking and Reading and Thinking section, the influence in examples has been shown. Thus, use the Present Perfect Tense is appropriate. However, in order to show the justice or weaken the doer of the behavior/action, it’s better to use the Present Perfect Passive Voice than the Present Perfect Tense. Besides, having learned to use the Present Perfect Passive Voice, students can beautify their language in their writing. 1. Learn the structure of the Present Perfect Passive Voice and its functions. 2. Learn to change the sentences with the Present Perfect Passive Voice into the sentences with the Present Perfect Passive Voice. 3. Learn to write sentences with the Present Perfect Passive Voice flexibly according to the context. 1. Learn the structure of the Present Perfect Passive Voice and its functions. 2. Learn to change the sentences with the Present Perfect Passive Voice into the sentences with the Present Perfect Passive Voice. 3. Learn to write sentences with the Present Perfect Passive Voice flexibly according to the context. Step 1 Observe the following sentences, then change the sentences into passive voice.He has been selected to take part in the sports meeting．(肯定句)他已被挑選出來參加運動會。The ink has not been removed from his overcoat．(否定句)墨跡還沒有從他外套上去掉。
新人教版高中英語必修2Unit 3 The Internet-Listening &Speaking＆Talking教案二
From the pictures in the text and the title--- choose the best app, we can know that this part is about how to save money by using apps.Step 2 While-listening1. Laura and Xiao Bo are talking about apps. Listen to their conversation and find out what apps they want.Xiao Bo is looking for a(n) exercise app to help him get in shape.Laura would like an app for getting rich and another that will make her grades better.2. Listen again. Are the sentences true T or false F?1). Both of Xiao Bo's apps keep track of the steps he takes._____2). Xiao Bo's second app can help him make a fitness plan._____3). Laura needs an app that will help her get discounts.______4). Laura needs an app that will add money to her bank account._______F T F T3. Listen once more and tick the sentence you hear. Underline the words used to express predictions, guesses, and beliefs.Predictions, Guesses, and Beliefs________It might help me walk more.________My guess is that it wouldn't work.________I imagine this app would help me get fit faster________I suppose that would be good.________I guess you could save a little with this app.________I suppose there would be some problems, too.________I believe this app could help me get thinner.
新人教版高中英語必修2Unit 3 The Internet-Reading and Thinking教案二
Q5：What's Jan's next goal?Her next goal is to start a charity website to raise money for children in poor countries.Q6：What can we learn from her experiences?We learn that when we go through tough times, we can find help and support from other people online. We learn that we can feel less lonelyStep 5: While reading---rethinkingQ1: What is Jan’s attitude to the Internet ?Thankful/Grateful, because it has changed her and her life.Q2: What writing skills is used in the article ?Examples(Jan’s example, the 59-year-old man’s and the 61-year-old woman’s example)Q3: Can you get the main idea of the article ?The Internet has changed Jan’s life/Jan’s life has been changed by the Internet.Step 6 Post reading---Retell the storyMuch has been written about the wonders of the World Wide Web. There are countless articles (1)telling(tell) us how the Internet has made our lives more convenient. But the Internet has done a lot (2)more(much) for people than simply make life more convenient. People’s lives (3) have been changed(change) by online communities and social networks so far. Take Jan for example, who developed a serious illness that made her (4)stuck(stick) at home with only her computer to keep (5)her(she) company. She joined an online group (6)where she could share problems, support and advice with others. She considered the ability to remove the distance between people as one of the greatest (7)benefits(benefit). She was so inspired (8)that she started an IT club in which many people have been helped. She has started to learn more about how to use the Internet to make society better. Her next goal is to start a charity website to raise money (9)for children in poor countries. Jan’s life has been (10)greatly(great) improved by the Internet.
新人教版高中英語必修2Unit 3 The Internet-Reading for Writing教案二
8. However, the more polite you are, the less likely it is you will be attacked. 然而, 你越有禮貌, 你被攻擊的可能性就越小。 Step 8 Writing---the articleHow to stay safe in the online chat roomToday I thought I’d blog about a question that has been asked many times--- how do you stay safe online and avoid bad experiences in the online chat room ? I’m not an expert, but many years as a blogger have taught me a thing or two.First of all, there’s the golden rule of the Internet: keep out of what makes you uneasy. Don’t post comments or click on anything. Second, protect your privacy. Don’t give out too much private information like your address, phone numbers, the ID numbers, etc. Third, be polite. If you are polite to others on the Internet, you won’t be attacked in normal situation. Finally, don’t believe in others easily and never meet someone you met online alone. It is very dangerous.Have you had any bad experiences online, or do you have some good advice for staying safe? Post your comments below!Step 9 Pair workExchange drafts with a partner. Use this checklist to help your partner revise his/her draft.1. Does the writer tell the reader what he/she know about the topic ?2. Are the tips and suggestions well organised ?3. Has the writer defined the new words ?4. Does the author include examples, comparison, or explanations ?5. Does the writer end by asking readers to leave comments and/or suggestions ?6. Can you find any grammar or spelling mistakes.Step 6 HomeworkPut up your revised draft in the classroom or read it to your class.
新人教版高中英語必修2Unit 3 The Internet-Reading For Writing教案一
⑦identity theft 身份盜竊⑧chat room 聊天室⑨draft your blog post 起草博客帖子⑩post embarrassing photos 張貼尷尬照片 【話題句式】 1. How do you stay safe online and avoid bad experiences on the Internet? 你如何在網(wǎng)上保持安全, 避免在網(wǎng)上的不良經(jīng)歷? 2. I’m not an expert, but many years as a blogger have taught me a thing or two. 我不是專家, 但作為一個博主, 我已經(jīng)學(xué)了好幾年了。 3. If you see or read something that makes you feel uncomfortable, leave the site immediately. 如果你看到或讀到一些讓你覺得不舒服的東西, 立即離開這個網(wǎng)站。4. Don’t give out your address or phone number. 別告訴別人你的地址或電話號碼。 5. Identity theft is a common and serious problem. 身份盜竊是一個常見而嚴(yán)重的問題。6. Being online is no excuse for being rude, and you don’t want to become a target for a troll or cyberbully. 上網(wǎng)并不是無禮的借口, 你也不想成為發(fā)挑釁帖子的人或網(wǎng)絡(luò)惡霸的目標(biāo)。 7. Trolls often use several false names so that they can stay on a site. 發(fā)挑釁帖子的人經(jīng)常使用幾個假名, 這樣他們就可以留在一個網(wǎng)站上。8. However, the more polite you are, the less likely it is you will be attacked. 然而, 你越有禮貌, 你被攻擊的可能性就越小。
人教版新課標(biāo)高中物理必修2平拋運動教案2篇
（五）平拋運動規(guī)律的應(yīng)用例1：一架老式飛機在高出海面45m的高處，以80m/s的速度水平飛行，為了使飛機上投下的炸彈落在停在海面上的敵船，應(yīng)該在與轟炸目標(biāo)的水平距離為多遠(yuǎn)的地方投彈?不計空氣阻力。分析：對于這道題我們可以從以下幾個方面來考慮：(1)從水平飛行的飛機上投下的炸彈，做什么運動?為什么?(2)炸彈的這種運動可分解為哪兩個什么樣的分運動?3)要想使炸彈投到指定的目標(biāo)處，你認(rèn)為炸彈落地前在水平方向通過的距離與投彈時飛機離目標(biāo)的水平距離之間有什么關(guān)系?拓展：1、式飛機在高出海面45m的高處，以80m/s的速度水平飛行，尾追一艘以15m/s逃逸的敵船，為了使飛機上投下的炸彈正好擊中敵船，應(yīng)該在與轟炸目標(biāo)的水平距離為多遠(yuǎn)的地方投彈?不計空氣阻力。2、在一次摩托車跨越壕溝的表演中，摩托車從壕溝的一側(cè)以速度v＝40m/s沿水平方向向另一側(cè)，壕溝兩側(cè)的高度及寬度如圖所示，摩托車可看做質(zhì)點，不計空氣阻力。（1）判斷摩托車能否跨越壕溝？請計算說明（2）若能跨過，求落地速度？
人教版新課標(biāo)高中物理必修1彈力教案2篇
一般情況下，凡是支持物對物體的支持力，都是支持物因發(fā)生形變而對物體產(chǎn)生彈力。所以支持力的方向總是垂直于支持面而指向被支持的物體。例1：放在水平桌面上的書書由于重力的作用而壓迫桌面，使書和桌面同時發(fā)生微小形變，要恢復(fù)原狀，對桌面產(chǎn)生垂直于桌面向下的彈力f1，這就是書對桌面的壓力；桌面由于發(fā)生微小的形變，對書產(chǎn)生垂直于書面向上的彈力f2，這就是桌面對書的支持力。學(xué)生分析：靜止地放在傾斜木板上的書，書對木板的壓力和木板對書的支持力。并畫出力的示意圖。結(jié)論：壓力、支持力都是彈力。壓力的方向總是垂直于支持面而指向被壓的物體，支持力的方向總是垂直于支持面而指向被支持的物體。引導(dǎo)學(xué)生分析靜止時，懸繩對重物的拉力及方向。引導(dǎo)得出：懸掛物由于重力的作用而拉緊懸繩，使重物、懸繩同時發(fā)生微小的形變。重物由于發(fā)生微小的形變，對懸繩產(chǎn)生豎直向下的彈力f1，這是物對繩的拉力；懸繩由于發(fā)生微小形變，對物產(chǎn)生豎直向上的彈力f2，這就是繩對物體的拉力。
人教版新課標(biāo)高中物理必修1力的分解教案2篇
一、教材內(nèi)容經(jīng)全國中小學(xué)教材審定委員會2004年初審查通過，人教育出版社出版的普通高中課程標(biāo)準(zhǔn)實驗教科書《物理必修①》，第三章第5節(jié)內(nèi)容“力的分解”。二、教學(xué)目標(biāo)1．知識與技能（1）理解分力的概念，理解力的分解是力的合成的逆運算，遵循平行四邊形定則。（2）初步掌握一般情況下力的分解要根據(jù)實際需要來確定分力的方向。（3）會用作圖法和直角三角形的知識求分力。（4）能區(qū)別矢量和標(biāo)量，知道三角形定則，了解三角形定則與平行四邊形定則的實質(zhì)是一樣的。2．過程與方法（1）進(jìn)一步領(lǐng)會“等效替代”的思想方法。（2）通過探究嘗試發(fā)現(xiàn)問題、探索問題、解決問題能力。（3）掌握應(yīng)用數(shù)學(xué)知識解決物理問題的能力。3．情感態(tài)度與價值觀（1）通過猜測與探究享受成功的快樂。（2）感受物理就在身邊，有將物理知識應(yīng)用于生活和生產(chǎn)實驗的意識。三、教學(xué)重點、難點在具體問題中如何根據(jù)力的實際作用效果和平行四邊形定則進(jìn)行力的分解。
人教版新課標(biāo)高中物理必修1摩擦力教案2篇
l．知識與技能：（1）知道摩擦力產(chǎn)生的條件。（2）能在簡單問題中，根據(jù)物體的運動狀態(tài)，判斷靜摩擦力的有無、大小和方向；知道存在著最大靜摩擦力。（3）掌握動磨擦因數(shù)，會在具體問題中計算滑動磨擦力，掌握判定摩擦力方向的方法。（4）知道影響到摩擦因數(shù)的因素。2．過程與方法：通過觀察演示實驗，概括出摩擦力產(chǎn)生的條件及摩擦力的特點，培養(yǎng)學(xué)生的觀察、概括能力。通過靜摩擦力與滑動摩擦力的區(qū)別對比，培養(yǎng)學(xué)生分析綜合能力。3．情感態(tài)度價值觀：在分析物體所受摩擦力時，突出主要矛盾，忽略次要因素及無關(guān)因素，總結(jié)出摩擦力產(chǎn)生的條件和規(guī)律。二、重點、難點分析1．本節(jié)課的內(nèi)容分滑動摩擦力和靜摩擦力兩部分。重點是摩擦力產(chǎn)生的條件、特性和規(guī)律，通過演示實驗得出關(guān)系f=μN。2．難點是學(xué)生有初中的知識，往往誤認(rèn)為壓力N的大小總是跟滑動物體所受的重力相等，因此必須指出只有當(dāng)兩物體的接觸面垂直，物體在水平拉力作用下，沿水平面滑動時，壓力N的大小才跟物體所受的重力相等。
人教版新課標(biāo)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(dāng)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(dāng)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(dāng)實際功率大于額定功率以后，這種情況不可能實現(xiàn)。
人教版新課標(biāo)高中物理必修2向心力教案2篇
3．進(jìn)一步體會力是產(chǎn)生加速度的原因，并通過牛頓第二定律來理解勻速圓周運動、變速圓周運動及一般曲線運動的各自特點。（三）、情感、態(tài)度與價值觀1．在實驗中，培養(yǎng)學(xué)生動手、探究的習(xí)慣。2．體會實驗的意義，感受成功的快樂，激發(fā)學(xué)生探究問題的熱情、樂于學(xué)習(xí)的品質(zhì)。教學(xué)重點1．體會牛頓第二定律在向心力上的應(yīng)用。2．明確向心力的意義、作用、公式及其變形，并經(jīng)行計算。教學(xué)難點1．對向心力的理解及來源的尋找。2．運用向心力、向心加速度的知識解決圓周運動問題。教學(xué)過程（一）、 引入新課：復(fù)習(xí)提問：勻速圓周運動的物體的加速度——向心加速度，它的方向和大小有何特點呢？學(xué)生回答后進(jìn)一步引導(dǎo)：那做勻速圓周運動物體的受力有什么特點呢？是什么力使物體做圓周運動而不沿直線飛出？請同學(xué)們先閱讀教材