圆周运动课件.ppt

单击此处编辑母版标题样式,,单击此处编辑母版文本样式,,第二级,,第三级,,第四级,,第五级,,,,*,单击此处编辑母版标题样式,,单击此处编辑母版文本样式,,第二级,,第三级,,第四级,,第五级,,,,*,第五章 曲线运动,第四节 圆周运动,一,.,认识圆周运动,,圆周运动特征：,,质点的轨迹是圆周,(,圆弧,),、,,具有周期性,转盘,水流星,地球仪,圆锥摆,在物理学中，把质点的运动轨迹是圆或圆弧的一部分的运动叫做圆周运动一、圆周运动的定义：,,圆周运动的位置如何确定？如何判断快慢？,,,,,,,,,时 钟,,,弧长,,转角,相同时间,内通过的,弧长,相同时间,内转过的,角度,探究,,,,,,,,,,描述快慢的物理量：线速度,ν,、,角速度,ω,、,周期,Τ,、,转速n,,,二、,,思考：描述圆周运动快慢的物理量,,,,,,,,两物体均做圆周运动，怎样比较它们运动的快慢呢？,,,,,比较物体在一段时间内通过的圆弧的长短,比较物体在一段时间内半径转过的角度大小,比较物体转过一圈所用时间的多少,比较物体在一段时间内转过的圈数,描述圆周运动快慢的物理量,,,,1,、物理意义：描述质点沿圆弧运动的快慢,。

2,、定义,3,、公式,,（一）线速度,4,、单位,m/s,,v,,=,Δ,t,Δ,s,5,、矢量,方向：沿圆 周该点的切线方向,Δs,是弧长并非位移,当,Δt,很小很小时（趋近零），弧长,Δs,就等于物体的位移，式中的,v,，就是直线运动中学过的瞬时速度,∆s,6,、注意： 为了详细研究,,圆周运动，在实际应用中我们考虑得较多是瞬时线速度，很少去考虑平均线速度，,如无特殊说明，圆周运动线速度均指瞬时线速度线速度就是瞬时速度,.,,,,v,,v,,v,,o,匀速圆周运动,物体,沿着圆周,运动，并且,线速度的大小处处相等,，这种运动叫做,匀速圆周运动,率,匀速圆周运动中的“匀速”指速度不变吗？,匀速圆周运动是一 种变加速曲线运动,7.,思考：,,,(1),匀速圆周运动的定义,(2),匀速圆周运动的运动性质：,zxxk,描述圆周运动快慢的物理量,,,,1、物理意义：描述质点转过圆心角（,绕圆心转动,）的快慢2,、定义,3,、公式,（二）角速度,4,、单位,rad/s,,ω,=,Δ,t,Δ,θ,,,Δ,θ,Δθ,采用弧度制,5,、说明：,,,匀速圆周运动是角速度不变的运动描述圆周运动快慢的物理量,,,,,定义,,,,符号,,,,单位,,,,物理意义,,,,关系,,,,物体在单位时间所转过的圈数,n,r/s,或,r/min,描述物体做圆周运动的快慢,,物体周期性运动一周所用的时间,物体在1秒内所完成周期性运动的次数,（即转动的圈数）,T,f,s,H,z,转速,周期,频率,（三）转速、周期、频率,,3、匀速圆周运动是周期不变的运动！,2、匀速圆周运动是角速度不变的运动！,1、匀速圆周运动是线速度大小不变方向时刻变化的运动！,归纳总结：,,,,,,,,,,,,,,,,,,1,、做匀速圆周运动的物体，线速度,,不变，,,,,时刻在变，线速度是,,(,恒量或变量,),,,匀速圆周运动的性质是,,,,,,匀速的含义是,,。

大小,方向,变量,变加速曲线运动,线速度的大小不变,,同步练习：,1.,线速度、角速度与周期的关系？,2.,线速度与角速度的关系？,3.,角速度与转速之间的关系？,（四）思考：,学,.,科,.,网,.,如何描述匀速圆周运动的快慢？,1.,线速度,——,质点通过的圆弧长,Δ,s,跟所用时间,Δ,t,的比值3.,周期,——,物体作匀速圆周运动一周所用的时间5.,转速,——,单位时间内转过的圈数2.,角速度,—,质点所在的半径转过的角度,Δθ,跟所用时间,Δ,t,的比值即：,单位：米,/,秒，,m/s,即：,单位：弧度,/,秒，,rad/s,即：,单位：秒，,s,即：,单位：转,/,秒，,r/s,4.,频率,——1s,时间内完成圆周运动的次数即：,单位：赫兹，,Hz,,ω,=,Δ,t,Δ,θ,第,1,节 圆周运动,物体做半径为,r,,的匀速圆周运动：,,⑴它运动一周所用的时间叫,_______,,用,T,表示它在周期,T,内转过的弧长为,______,,,,由此可知它的线速度为,,⑵一个周期,T,内转过的角度为,______,弧度,,,,,物体的角速度为,,弧度,/,秒⑶线速度与角速度的关系：,,。

周期,2,r,2,,,思考题,：,【,例题,】,机械手表的时针、分针、秒针的角速度之比：,,,A.1:60:30,,B.1:12:360,,C.1:12:720,,D.1:60:720,第,1,节 描述圆周运动,【,例题,】,物体做匀速圆周运动时，下列哪些量不变？,,,A.,速率,B.,速度,C.,角速度,D.,周期,ACD,C,3.,钟表里的时针、分针、秒针的角速度之比为,_______,,1:12:720,2.,某钟表上秒针、分针的长度比为,d,1,：,d,2,＝,1,：,2,，求：,,,A,：秒针、分针转动的角速度之比是,__________,,B,：秒针、分针尖端的线速度之比是,__________,,30,：,1,60,：,1,同步练习：,zxxk,1,）,传动装置线速度的关系,a,、,皮带传动－,线速度相等,b,、齿轮传动－线速度相等,,,同一传动各轮边缘上的点线速度相同,（五）两个重要的结论,,,,,,,,A,B,C,2,）同一轮上各点的角速度关系,同一轮上各点的角速度相同,,,小结：,同一轮上各点的角速度相同,,同一传动各轮边缘上线速度相同,1,、比较图中,A,、,B,、,C,三点线速度的的大小关系,,,,,A,B,,,C,,,,,B,A,,,C,A,、,B,、,C,三点的线速度大小相等,,四、课堂练习,思考,2,、地球上的物体随着地球一起饶地轴自转。

地球上不同纬度的物体的周期一样吗,?,角速度一样吗,?,线速度大小一样吗,?,,,,,,,,O,R,,,θ,R,',O,',,,O,R,R,',,θ,O,',,,,,A,B,C,3.,已知,r,A,:r,B,:r,C,=4:2:1,，试求：,,2 : 1 : 1,1 : 1 : 2,课后作业：,,1.用圆规、硬纸卡片 自制两个半径不同的圆盘，体会摩擦传动系统中边缘点线速度相同的特点,,2.课本P18 问题与练习1. 2. 5,,3.课后练习：导学案上的达标检测题,谢谢大家!,第五章 曲线运动,第四节 圆周运动,一,.,认识圆周运动,,圆周运动特征：,,质点的轨迹是圆周,(,圆弧,),、,,具有周期性,转盘,水流星,地球仪,圆锥摆,在物理学中，把质点的运动轨迹是圆或圆弧的一部分的运动叫做圆周运动一、圆周运动的定义：,,圆周运动的位置如何确定？如何判断快慢？,,,,,,,,,时 钟,,,弧长,,转角,相同时间,内通过的,弧长,相同时间,内转过的,角度,探究,,,,,,,,,,描述快慢的物理量：线速度,ν,、,角速度,ω,、,周期,Τ,、,转速n,,,二、,,思考：描述圆周运动快慢的物理量,,,,,,,,两物体均做圆周运动，怎样比较它们运动的快慢呢？,,,,,比较物体在一段时间内通过的圆弧的长短,比较物体在一段时间内半径转过的角度大小,比较物体转过一圈所用时间的多少,比较物体在一段时间内转过的圈数,描述圆周运动快慢的物理量,,,,1,、物理意义：描述质点沿圆弧运动的快慢,。

2,、定义,3,、公式,,（一）线速度,4,、单位,m/s,,v,,=,Δ,t,Δ,s,5,、矢量,方向：沿圆 周该点的切线方向,Δs,是弧长并非位移,当,Δt,很小很小时（趋近零），弧长,Δs,就等于物体的位移，式中的,v,，就是直线运动中学过的瞬时速度,∆s,6,、注意： 为了详细研究,,圆周运动，在实际应用中我们考虑得较多是瞬时线速度，很少去考虑平均线速度，,如无特殊说明，圆周运动线速度均指瞬时线速度线速度就是瞬时速度,.,,,,v,,v,,v,,o,匀速圆周运动,物体,沿着圆周,运动，并且,线速度的大小处处相等,，这种运动叫做,匀速圆周运动,率,匀速圆周运动中的“匀速”指速度不变吗？,匀速圆周运动是一 种变加速曲线运动,7.,思考：,,,(1),匀速圆周运动的定义,(2),匀速圆周运动的运动性质：,zxxk,描述圆周运动快慢的物理量,,,,1、物理意义：描述质点转过圆心角（,绕圆心转动,）的快慢2,、定义,3,、公式,（二）角速度,4,、单位,rad/s,,ω,=,Δ,t,Δ,θ,,,Δ,θ,Δθ,采用弧度制,5,、说明：,,,匀速圆周运动是角速度不变的运动描述圆周运动快慢的物理量,,,,,定义,,,,符号,,,,单位,,,,物理意义,,,,关系,,,,物体在单位时间所转过的圈数,n,r/s,或,r/min,描述物体做圆周运动的快慢,,物体周期性运动一周所用的时间,物体在1秒内所完成周期性运动的次数,（即转动的圈数）,T,f,s,H,z,转速,周期,频率,（三）转速、周期、频率,,3、匀速圆周运动是周期不变的运动！,2、匀速圆周运动是角速度不变的运动！,1、匀速圆周运动是线速度大小不变方向时刻变化的运动！,归纳总结：,,,,,,,,,,,,,,,,,,1,、做匀速圆周运动的物体，线速度,,不变，,,,,时刻在变，线速度是,,(,恒量或变量,),,,匀速圆周运动的性质是,,,,,,匀速的含义是,,。

大小,方向,变量,变加速曲线运动,线速度的大小不变,,同步练习：,1.,线速度、角速度与周期的关系？,2.,线速度与角速度的关系？,3.,角速度与转速之间的关系？,（四）思考：,学,.,科,.,网,.,如何描述匀速圆周运动的快慢？,1.,线速度,——,质点通过的圆弧长,Δ,s,跟所用时间,Δ,t,的比值3.,周期,——,物体作匀速圆周运动一周所用的时间5.,转速,——,单位时间内转过的圈数2.,角速度,—,质点所在的半径转过的角度,Δθ,跟所用时间,Δ,t,的比值即：,单位：米,/,秒，,m/s,即：,单位：弧度,/,秒，,rad/s,即：,单位：秒，,s,即：,单位：转,/,秒，,r/s,4.,频率,——1s,时间内完成圆周运动的次数即：,单位：赫兹，,Hz,,ω,=,Δ,t,Δ,θ,第,1,节 圆周运动,物体做半径为,r,,的匀速圆周运动：,,⑴它运动一周所用的时间叫,_______,,用,T,表示 它在周期,T,内转过的弧长为,______,,由此可知它的线速度为,,⑵一个周期,T,内转过的角度为,______,弧度,,,物体的角速度为,,弧度,/,秒⑶线速度与角速度的关系：,,。

周期,2,r,2,,,思考题,：,【,例题,】,机械手表的时针、分针、秒针的角速度之比：,A.1:60:30,,B.1:12:360 C.1:12:720,,D.1:60:720,第,1,节 描述圆周运动,【,例题,】,物体做匀速圆周运动时，下列哪些量不变？,A.,速率,B.,速度,C.,角速度,D.,周期,ACD,C,3.,钟表里的时针、分针、秒针的角速度之比为,_______,,1:12:720,2.,某钟表上秒针、分针的长度比为,d,1,：,d,2,＝,1,：,2,，求：,,,A,：秒针、分针转动的角速度之比是,__________,,B,：秒针、分针尖端的线速度之比是,__________,,30,：,1,60,：,1,同步练习：,zxxk,1,）,传动装置线速度的关系,a,、,皮带传动－,线速度相等,b,、齿轮传动－线速度相等,,,同一传动各轮边缘上的点线速度相同,（五）两个重要的结论,,,,,,,,A,B,C,2,）同一轮上各点的角速度关系,同一轮上各点的角速度相同,,,小结：,同一轮上各点的角速度相同,,同一传动各轮边缘上线速度相同,1,、比较图中,A,、,B,、,C,三点线速度的的大小关系,,,,,A,B,,,C,,,,,B,A,,,C,A,、,B,、,C,三点的线速度大小相等,,四、课堂练习,思考,2,、地球上的物体随着地球一起饶地轴自转。

地球上不同纬度的物体的周期一样吗,?,角速度一样吗,?,线速度大小一样吗,?,,,,,,,,O,R,,,θ,R,',O,',,,O,R,R,',,θ,O,',,,,,A,B,C,3.,已知,r,A,:r,B,:r,C,=4:2:1,，试求：,,2 : 1 : 1,1 : 1 : 2,课后作业：,,1.用圆规、硬纸卡片 自制两个半径不同的圆盘，体会摩擦传动系统中边缘点线速度相同的特点,,2.课本P18 问题与练习1. 2. 5,,3.课后练习：导学案上的达标检测题,谢谢大家!,教师说课,PPT,1,,教材分析,,2,,学情分析,,3,,教学理念,,4,,教学方法,,5,,教学过程,,教学反思,More than 50% of your traffic comes from social media platforms. So how do you go about executing a content strategy,AND,keep track of what,’,s trending?,,Here are a few tools to make the going easy,…,,,教学重点,,,教学难点,高龄游客的特征,如何灵活提供服务,教学,目标,!,,,,Click,here to,add your,text. Click here to add your text. Click here to add your,text.,知识目标,01,能力目标,02,情感目标,03,Click,here to,add your,text. Click here to add your text. Click here to add your text.,Click,here to,add your,text. Click here to add your text. Click here to add your text.,学情,,分析,,,,,单击此处添加您的标题文字单击此处添加您的标题文字单击,1.,学生原有的基础,单击此处添加您的标题文字单击此处添加您的标题文字单击,2.,学生先学的基础,单击此处添加您的标题文字单击此处添加您的标题文字单击,3.,学生的关注点,©,1999 - 2014 IX Web Hosting. All rights reserved,“,后茶馆式,”,,教学,!,一种关注学生学习获得知识的方法过程，提高学生学习效能的教学方式,教育指导,,思想,?,陶行知,:,知识来源于实践。

陶行知认识论：,,,行（实践）,,,知（知识）,,,行（实践）,教学,,教法,If not literally, at least to some extent! Try and get real time reviews on your products/services. Ask questions about what your customers expect next and try to fit some of those suggestions into your work. This helps establish a rapport and shows you off as being customer driven. After all, this is exactly what people look for - to be heard!,教学,,过程,,,,,,,5,分钟,..........,合理安排，分解目标,,20,分钟,..........,精确定位，明确目标,,18,分钟,...........,处方教学,,2,分钟,...........,布置作业,,Producing a Variety of Content..........9%,,No Answer............................................3%,第一节课,,合理安排，分解目标,Don,’,t always go for an all season look, get a makeover based on climate, festivities, etc; it gives a human touch to your business.,,A human business is more relatable than one that sounds also robotic and only sales oriented.,If overhauling the website every time isn,’,t a feasible option; opt for changing the looks of your social profiles.,,For example, bring some variation in your cover pictures on,Facebook,if you feel like keeping the profile picture constant to your business logo.,课前,课上,第一节课,,合理安排，分解目标,1 基本内容,,2 遵循原则,,3 使用方式,,4 指导思想,导学卡：,现代心理学研究认为，合作学习是最佳的学习方式，学生在合作中交流，交流中形成合作的意识,第一节课,,合理安排，分解目标,课堂随想：,人们在生产生活当中所经历的典型的富有多种意义的事件陈述。

第二节课,,精确定位，明确目标,案例分析：,教学,,过程,..because in a world where we have access to unlimited information in a matter of seconds, information based marketing has become vital.,一、案例关键点,第二节课,,精确定位，明确目标,,Its a social media tool that not just focuses on presenting you with what,’,s trending in your circles, but also helps you with CRM.,,It offers you insights on the popularity of your business,第二节课,,精确定位，明确目标,二、创设情景、导出难点,设计意图：,is by far the most popular tool in the market.,No one has the time to go through text heavy posts; but who doesn,’,t like bright images? Stock up on a lot of images that are unique to your business and fit them in your content strategy.,,They are the most shared post type across online platforms.,第二节课,,精确定位，明确目标,三、教师师范，学生点评,场景设计：,教学反思,,,,,,,,,,有行动,有感动,有活动,添加标题,添加标题,添加标题,板书,,设计,一、高龄游客的特征,,Cutting edge technology at reasonable prices. touch to your business.,,Scalability,,Ability to flex hosting plans in sync with the increasing needs of the website.,二、导游人员的服务,,The 24/7 technical support is prompt and never lets your website down.,,Security,,Certified by the likes of McAfee, IX servers provide the most secure environment for hosting your web logs.,With The Most Shared,Content Being..,Here,’,s Something,Good To Know!,60%,of consumers enjoy reading relevant content from brands.,82%,of consumers feel more positive about a company after reading custom content.,70%,of consumers feel closer to a company as a result of content marketing.,Gather,Topics!,Before you start creating your content plan and strategy, it,’,s always better to research and shortlist a handful of topics that are not just relevant to your business, but also trending in your circles.,,Talking about,“,what,’,s in,”,helps you keep your audience hooked.,Tell Your,Story!,People want to know the thought process behind your business and how it came about to be. Share your story and your unique experiences along the way. It makes your business more relatable.,Swayy,Its a tool that analyzes your social community, matches the most relevant content from around the web and offers it on your dashboard,,,helps you build a relationship between your content and your followers.,,Swayy,RebelMouse,Claimed as the front page of social media,,,helps you curate content for all your online profiles on a single dashboard based on what your business is known for and what conversations your audience has been engaging in.,,RebelMouse,谢谢大家,教师说课,PPT,1,,教材分析,,2,,学情分析,,3,,教学理念,,4,,教学方法,,5,,教学过程,,教学反思,More than 50% of your traffic comes from social media platforms. So how do you go about executing a content strategy,AND,keep track of what,’,s trending?,,Here are a few tools to make the going easy,…,,,教学重点,,,教学难点,高龄游客的特征,如何灵活提供服务,教学,目标,!,,,,Click,here to,add your,text. Click here to add your text. Click here to add your,text.,知识目标,01,能力目标,02,情感目标,03,Click,here to,add your,text. Click here to add your text. Click here to add your text.,Click,here to,add your,text. Click here to add your text. Click here to add your text.,学情,,分析,,,,,单击此处添加您的标题文字单击此处添加您的标题文字单击,1.,学生原有的基础,单击此处添加您的标题文字单击此处添加您的标题文字单击,2.,学生先学的基础,单击此处添加您的标题文字单击此处添加您的标题文字单击,3.,学生的关注点,©,1999 - 2014 IX Web Hosting. All rights reserved,“,后茶馆式,”,,教学,!,一种关注学生学习获得知识的方法过程，提高学生学习效能的教学方式,教育指导,,思想,?,陶行知,:,知识来源于实践。

陶行知认识论：,,,行（实践）,,,知（知识）,,,行（实践）,教学,,教法,If not literally, at least to some extent! Try and get real time reviews on your products/services. Ask questions about what your customers expect next and try to fit some of those suggestions into your work. This helps establish a rapport and shows you off as being customer driven. After all, this is exactly what people look for - to be heard!,教学,,过程,,,,,,,5,分钟,..........,合理安排，分解目标,,20,分钟,..........,精确定位，明确目标,,18,分钟,...........,处方教学,,2,分钟,...........,布置作业,,Producing a Variety of Content..........9%,,No Answer............................................3%,第一节课,,合理安排，分解目标,Don,’,t always go for an all season look, get a makeover based on climate, festivities, etc; it gives a human touch to your business.,,A human business is more relatable than one that sounds also robotic and only sales oriented.,If overhauling the website every time isn,’,t a feasible option; opt for changing the looks of your social profiles.,,For example, bring some variation in your cover pictures on,Facebook,if you feel like keeping the profile picture constant to your business logo.,课前,课上,第一节课,,合理安排，分解目标,1 基本内容,,2 遵循原则,,3 使用方式,,4 指导思想,导学卡：,现代心理学研究认为，合作学习是最佳的学习方式，学生在合作中交流，交流中形成合作的意识,第一节课,,合理安排，分解目标,课堂随想：,人们在生产生活当中所经历的典型的富有多种意义的事件陈述。

第二节课,,精确定位，明确目标,案例分析：,教学,,过程,..because in a world where we have access to unlimited information in a matter of seconds, information based marketing has become vital.,一、案例关键点,第二节课,,精确定位，明确目标,,Its a social media tool that not just focuses on presenting you with what,’,s trending in your circles, but also helps you with CRM.,,It offers you insights on the popularity of your business,第二节课,,精确定位，明确目标,二、创设情景、导出难点,设计意图：,is by far the most popular tool in the market.,No one has the time to go through text heavy posts; but who doesn,’,t like bright images? Stock up on a lot of images that are unique to your business and fit them in your content strategy.,,They are the most shared post type across online platforms.,第二节课,,精确定位，明确目标,三、教师师范，学生点评,场景设计：,教学反思,,,,,,,,,,有行动,有感动,有活动,添加标题,添加标题,添加标题,板书,,设计,一、高龄游客的特征,,Cutting edge technology at reasonable prices. touch to your business.,,Scalability,,Ability to flex hosting plans in sync with the increasing needs of the website.,二、导游人员的服务,,The 24/7 technical support is prompt and never lets your website down.,,Security,,Certified by the likes of McAfee, IX servers provide the most secure environment for hosting your web logs.,With The Most Shared,Content Being..,Here,’,s Something,Good To Know!,60%,of consumers enjoy reading relevant content from brands.,82%,of consumers feel more positive about a company after reading custom content.,70%,of consumers feel closer to a company as a result of content marketing.,Gather,Topics!,Before you start creating your content plan and strategy, it,’,s always better to research and shortlist a handful of topics that are not just relevant to your business, but also trending in your circles.,,Talking about,“,what,’,s in,”,helps you keep your audience hooked.,Tell Your,Story!,People want to know the thought process behind your business and how it came about to be. Share your story and your unique experiences along the way. It makes your business more relatable.,Swayy,Its a tool that analyzes your social community, matches the most relevant content from around the web and offers it on your dashboard,,,helps you build a relationship between your content and your followers.,,Swayy,RebelMouse,Claimed as the front page of social media,,,helps you curate content for all your online profiles on a single dashboard based on what your business is known for and what conversations your audience has been engaging in.,,RebelMouse,谢谢大家,。