2017届上海市普陀区高三下学期质量调研物理试卷(带解析)

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2017年上海市普通高中学业水平等级性考试物理试题+Word版含答案

2017年上海市普通高中学业水平等级性考试物理试卷考生注意：1．试卷满分100分，考试时间60分钟。

2．本考试分设试卷和答题纸。

试卷包括三部分，第一部分为选择题，第二部分为填空题，第三部分为综台题。

3．答题前，务必在答题纸上填写姓名、报名号、考场号和座位号，并将核对后的条形码贴在指定位置上。

作答必须涂或写在答题纸上，在试卷上作答一律不得分。

第一部分的作答必须涂在答题纸上相应的区域，第二、三部分的作答必须写在答题纸上与试卷题号对应的位置。

一、选择题（共40分。

第1-8小题，每小题3分，第9-12小题，每小题4分。

每小题只有一个正确答案。

）1．由放射性元素放出的氦核流被称为（）（A ）阴极射线（B ）α射线（C ）β射线（D ）γ射线2．光子的能量与其（）（A ）频率成正比（B ）波长成正比（C ）速度成正比（D ）速度平方成正比3．在同位素氢、氘，氚的核内具有相同的（）（A ）核子数（B ）电子数（C ）中子数（D ）质子数4．用单色光照射位于竖直平面内的肥皂液薄膜，所观察到的干涉条纹为（）5．如图，在匀强电场中，悬线一端固定于地面，另一端拉住一个带电小球，使之处于静止状态。

忽略空气阻力，当悬线断裂后，小球将做（）（A ）（B ）（C ）（D ）（A ）曲线运动（B ）匀速直线运动（C ）匀加速直线运动（D ）变加速直线运动6．一碗水置于火车车厢内的水平桌面上。

当火车向右做匀减速运动时，水面形状接近于图（）7．从大型加速器射出的电子束总能量约为500GeV （1GeV ＝1.6×10-10J ），此能量最接近（）（A ）一只爬行的蜗牛的动能（B ）一个奔跑的孩子的动能（C ）一辆行驶的轿车的动能（D ）一架飞行的客机的动能8．一个密闭容器由固定导热板分隔为体积相同的两部分，分别装有质量不等的同种气体。

当两部分气体稳定后，它们的（）（A ）密度相同（B ）分子数相同（C ）分子平均速率相同（D ）分子间平均距离相同9．将四个定值电阻a 、b 、c 、d 分别接入电路，测得相应的电流、电压值如图所示。

上海2017高三物理二模试卷(含答案)

（A ）（B ）（D ）（C ）2016学年第二学期高三物理教学质量检测试卷考生注意：1．答题前，务必在试卷与答题纸上填写学校、姓名、准考证号。

2．试卷满分100分，考试时间60分钟。

3．本考试分设试卷和答题纸。

试卷包括三大部分，第一部分为单项选择题，第二部分为填空题，第三部分为综合题。

4．作答必须涂或写在答题纸上相应的位置，在试卷上作答无效。

一、单项选择题（共40分，1至8题每小题3分，9至12题每小题4分。

每小题只有一个正确选项）1．气体温度由－20℃升高到27℃，用热力学温标表示是升高了（A ）47K（B ）320K（C ）226K（D ）280K2．将激光束照在如图所示的双缝上，在光屏上观察到的现象是下图中的3．如图所示，在演示光电效应的实验中，用弧光灯发出的紫外光照射锌板，发现与锌板导线相连接的验电器的指针张开一个角度。

则用下列电磁波照射锌板也一定能使验电器指针张开的是（A ）可见光（B ）γ射线（C ）红外光（D ）无线电波4．下列行星中有与地球类似的坚硬岩石外壳的是（A ）土星（B ）金星（C ）海王星（D ）天王星5．决定放射性元素衰变快慢的是（A ）环境温度的高低（B ）容器内压强的大小（C ）放射源质量的多少（D ）核内部自身的因素6．一气泡从湖底上升到湖面，若温度保持不变，此过程中气泡中气体（A ）分子的平均动能变大（B ）分子的平均动能变小（C ）分子间的作用力变大（D ）分子间的作用力变小 7．磁通量的单位Wb 用基本单位可表示为（A ）kg A·s（B ）kg·m 2A·s 2 （C ）kg·m 2A （D ）kgA·s28．两个物体从t =0时刻起先后开始做自由落体运动，同时落地，则正确描述它们运动的v-t 图是 9．如图，水平直线表示电场中的一条电场线，A 、B 为电场线上的两点。

一负点电荷仅在电场力作用下，从静止开始由A 向B 做匀加速运动。

2017上海物理水平等级考+答案

2017年上海市普通高中学业水平等级性考试物理试卷考生注意：1．试卷满分100分，考试时间60分钟。

2．本考试分设试卷和答题纸。

试卷包括三部分，第一部分为选择题，第二部分为填空题，第三部分为综台题。

3．答题前，务必在答题纸上填写姓名、报名号、考场号和座位号，并将核对后的条形码贴在指定位置上。

作答必须涂或写在答题纸上，在试卷上作答一律不得分。

第一部分的作答必须涂在答题纸上相应的区域，第二、三部分的作答必须写在答题纸上与试卷题号对应的位置。

一、选择题（共40分。

第1-8小题，每小题3分，第9-12小题，每小题4分。

每小题只有一个正确答案。

）1．由放射性元素放出的氦核流被称为（）（A）阴极射线（B）α射线（C）β射线（D）γ射线2．光子的能量与其（）（A）频率成正比（B）波长成正比（C）速度成正比（D）速度平方成正比3．在同位素氢、氘，氚的核内具有相同的（）（A）核子数（B）电子数（C）中子数（D）质子数4．用单色光照射位于竖直平面内的肥皂液薄膜，所观察到的干涉条纹为（）（A）（B）（C）（D）5．如图，在匀强电场中，悬线一端固定于地面，另一端拉住一个带电小球，使之处于静止状态。

忽略空气阻力，当悬线断裂后，小球将做（）（A ）曲线运动（B ）匀速直线运动（C ）匀加速直线运动（D ）变加速直线运动6．一碗水置于火车车厢内的水平桌面上。

上海市普陀区高三下学期物理二模质量检测试卷解析版

高三下学期物理二模质量检测试卷一、单项选择题1.用α粒子轰击得到了和一种粒子，这种粒子是〔〕A. 电子B. 质子C. 中子D. 正电子2.如图，某同学用激光器作为光源，在不透光的挡板上开一条窄缝，进行光的衍射实验。

在光屏上观察到的图样可能是图中的〔〕A. B. C. D.3.在“用DIS测变速直线运动的瞬时速度〞学生实验中，除需要用计算机、数据采集器、小车、轨道及配件外，还需要的仪器有〔〕A. 秒表B. 米尺C. 位移传感器D. 光电门传感器和挡光片4.用光照射某种金属，金属外表有电子逸出。

假设保持入射光的频率不变，减小入射光的强度，那么〔〕A. 光电子的最大初动能减小B. 光电子的最大初动能保持不变C. 可能无电子从金属外表逸出D. 单位时间内逸出的光电子数目不变m，每个气体分子的质量和体积分别为m和V0，那么阿伏加德罗常数N A可表示为〔〕A. N A=B. N A=C. N A=D. N A=6.质量相等的甲、乙、丙三个物体，分别只受大小为F1和F2、方向如图的两个力作用。

甲、乙、丙三个物体产生的加速度大小分别为a甲、a乙、a丙，那么〔〕A. a甲>a乙>a丙B. a丙>a乙>a甲C. a甲=a乙=a丙D. a乙>a丙>a甲7.如图，一弹性绳上有S1和S2两个波源，P点为S1和S2连线的中点。

两个波源同时开始振动发出两个相向传播的波1和波2，波长分别为λ1和λ2〔λ1>λ2〕，那么两列波〔〕A. 频率相同B. 同时到达P点C. 相遇时，发生干预现象D. 相遇时，波长均变大8.如图，人骑自行车在水平路面沿直线行进。

当人停止蹬车后，自行车受阻力作用做减速运动，直至速度减为零。

此过程中克服阻力做功为W，人停止蹬车时自行车的速度为v，符合实际情况的W－v图像为图中的〔〕A. B.C. D.9.一定质量的理想气体，温度为0ºC时压强为p0。

经过等容变化后，温度变为T=〔t+273〕K时压强为p，在此过程中气体温度每升高1ºC，对应压强的增量Δp不能表达为〔〕A. B. C. D.10.如图，地球在椭圆轨道上运动，太阳位于椭圆的一个焦点上。

2017届上海市普陀区高考二模试卷(含答案)

普陀区2016学年高三年级第二次学业质量调研测试英语学科试卷(时间120分钟，满分140分)考生注意：I.本试卷共12页。

满分140分。

考试时间120分钟。

2.答题前，考生务必在答题卡(纸)上用钢笔或水笔清楚填写姓名、准考证号，并用铅笔正确涂写准考证号。

3.答案必须全部涂写在答题卡(纸)上。

第1-20小题，第31-70小题，均由机器阅卷，考生应将代表正确答案的小方格用铅笔涂黑。

注意试题题号和答题纸编号一一对应，不能错位。

答案需要更改时，必须将原选项擦去，重新选择。

答案不能涂写在试卷上，涂写在试卷上一律不给分。

第21-30小题，第IV, V大题(即第72-75小题)和VI大题，其答案用钢笔或水笔写在答题纸上，如用铅笔答题或写在试卷上也一律不给分。

I. Listening Comprehension（略）II. Grammar and VocabularySection ADirections: After reading the passage below, fill in the blanks to make the passage coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word; for the other blanks, use one word that best fits each blank.Wildlife in DeclineThe populations of Earth’s wild vertebrates (脊椎动物）have declined by 58% over the past four decades, according to the Living Planet Report 2016 published by the World Wildlife Fund.Climate change and activities such as deforestation and poaching（偷猎）are in large part (21)______(blame) for the decline. If the trend continues, by 2020, the world (22)________(lose) two-thirds of its vertebrate biodiversity. “Sadly, there is no sign yet (23)________ this rate will decrease,” the report says.“Across land, fresh water and the oceans, human activities are forcing wildlife populations to the edge," says Marco Lambertini, director-general of WWF International.The Living Planet Report is published every two years. It aims to provide an assessment of the state of the world’s wildlife. The 2016 study included 3700 different species of birds, fish, mammals, amphibians and reptiles around the world. The team collected data from more than 3000 sources, including government statistics and surveys (24) ______ (carry) out by conservation groups. They then analyzed (25) ______ the population sizes had changed over time.Lambertini said some groups of animals had done worse than others. ''We do see particularly strong declines (26) ______ the freshwater environment. For freshwater species alone, the decline stands at 81% since 1970. This is related to the way that water (27)________(use) and taken out of freshwater systems, and also to the fragmentation（分裂）of freshwater systems through dam building, for example.”The report also highlighted other species, such as African elephants, (28) ________ nave suffered huge declines in recent years, and sharks, which are threatened by overfishing.(29) ________ ________ ________ all the terrifying facts, however, some conservationists say there is still hope. “One of the things that I think is the most important is that these wild animals haven't yet gone extinct,” said Robin Freeman，head of the Zoological Societ y of London. “On the whole, (30) ________ are not dying out, andthat means we still have opportunities to do something about the decline.”Section BDirections: Fill in each blank with a proper word chosen from the box. Each word can be used only once. Note that there is one word more than you need.My job puts me in contact with extraordinary leaders in many fields. So I tend to ____31____ a lot on leadership and how we can inspire successful teamwork, cooperation, and partnerships. In my experience, it is clear that the most successful leaders—both men and women—always demonstrate three ____32____ traits.TrustworthinessLeaders must set an example of honesty and justice and earn the trust of their teams through their everyday actions. When you do so with positive energy and enthusiasm for ____33____ goals and purpose, you can deeply connect with your team and customers. A culture of trust enables you to empower employees and ____34____ the foundation for communication, accountability, and continuous improvement.Compassion (共情)You can't forget that organizational success ____35____ from the hearts and minds of the men and women you lead. Rather than treating your people as you’d like to be treated, treat them as they would like to be treated. Small gestures like choosing face-to-face meetings or sending personal ____36____ can have an enormous impact on the spirits of the teams. In addition to thanks and praise, you must also understand people’s needs, pressures, and individual goals, which will allow you to lead them more effectively and ____37____ to their personal ambitions and professional development.DecisivenessIn times of ____38____ employees long for clarity. As a leader, you won't always have all of the answers—no one expects you to—so you must be open to listening and learning from others. Once you understand a particular challenge and ____39____ the options, you have to be confident in making bold and optimistic decisions.Successful leadership demands a lifelong commitment to sharpening these three basic skills. Wherever you have the opportunity to ____40____, the qualities of trustworthiness, compassion, and decisiveness are the keys to leadership and organizational success.Boxing is a popular sport that many people seem to be fascinated by. Newspapers, magazines and sports programmes on TV frequently ____41____ boxing matches. Professional boxers earn a lot of money, and successful boxers are ____42____ as big heroes.It seems to me that some people, especially men, find it ____43____ because it is an aggressive sport. When they watch a boxing match, they can t ____44____ the winning boxer, and this gives them the feeling of being a t ____45____ themselves. It is a fact that many people have feelings of aggressionIII. Reading ComprehensionSection ADirections: For each blank in the following passage there are four words or phrases marked A, B, C and D. Fill in each blank with the word or phrase that best fits the context.Boxing is a popular sport that many people seem to be fascinated by . Newspapers , magazines and sports programmes on TV frequently _________boxing matches . Professional boxers earn a lot of money , and successful boxers are _______as big heroes.It seems to me that people , especially men ,find it _______because it is an aggressive sport . When they watch a boxing match , they can _______ the winning boxer , and this gives them the feeling of being a ______ themselves . It is a fact that many people have feeling of aggression from time to time , but they cannot show their _______in their everyday lives . Watching a boxing match gives them an outlet for this aggression .However , there is a ______side to boxing . It can be a very dangerous sport . Although boxers wear gloves during the fights , and amateur boxers ______have to wear helmets , there have frequently been accident in both professional and amateur boxing , sometimes with ________consequences . Boxers have suffered from head injuries , and occasionally , fighters have even been killed as a result of being knocked out in the__________. Furthermore , studies have shown that there are often long-term effects of boxing , in the form of serious brain _______,even if a boxer has never been knocked out .I am personally not at all in ______of aggressive sports like boxing . I think it would be better if less time was _______to aggressive sports on TV, and we welcomed more men and women from non-aggressive sports as our heroes and heroines in our society . I believe that the world is aggressive enough already ! Of course , people like _______sports , and so do I , but I think that ______other people in an aggressive way is not something that should be regarded as a sport.41. A. broadcast B. cover C. host D. design42. A. kept B. individual C. thought D. treated43. A. appealing B. subjective C. violent D. challenging44. A. pick up B. believe in C. identify with D. long for45. A. winner B. spectator C. inspector D. trainer46. A. ambition B. aggression C. energy D. strength47. A. positive B. indifferent C. deadly D. negative48. A. otherwise B. somehow C. even D. barely49. A. dramatic B. eye-catching C. emotional D. special50. A. court B. ring C. pitch D. yard51. A. loss B. drain C. damage D. disorder52. A. favour B. process C. charge D. power53. A. shifted B. transformed C. given D. delivered54. A. competitive B. quiet C. cooperative D. regular55. A. invading B. insulting C. teasing D. hittingSection BDirections:Read the following three passages. Each passage is followed by several questions or unfinished statements. For each of them there are four choices marked A. B, C and D. Choose the one that fits best according to the information given in the passage you have just read.(A)FrankensteinFrankenstein was a book by Mary Shelly ----it’s been adapted for the screen dozens of times. The story of Frankenstein is told through a series of letters written by Captain Robert Walton to his sister , as he leads an expedition （长征）to the North Pole . On the way , he meets Victor Frankenstein , who tells Walton the story of his life. Frankenstein is the sur name of the guy who creates the monster . The monster doesn’t actually have a game . Anyway , Victor is a scientist who’s desperate to discover the secret of life . After years of study , he makes an enormous creature out of human remains and brings it to life . Victor intends it to be beautiful . Unfortunately , the creature turns out really hideous , and Victor runs away in terror . Although the monster is good and kind , humans are scared of it . When they mistreat it , the monster becomes angry and evil . Wanting revenge on its creator , the monster murders Dr. Frankenstein’s brother , his wife , and his best friend . When Victor figures out the monster is behind all the deaths , he swears to track it down and kill it .This book was written in 1816, right after a period called the Enlightenment . The Enlightenment emphasized the pursuit of knowledge and reason , and gave rise to the scientific method . Mary Shelley criticized the Enlightenment through the character of Victor Frankenstein , “ He is a neg ative example of an Enlightenment scientist -------he pursues knowledge at any cost , and his obsession with discovering the secret of life destroys him , as well as his friends and family .” Some Enlightenment thinkers might have seen such a loss as neces sary for the advancement of science , but not Mary Shelley . She and her husband , poet Percy Shelly , were part of the Romanic Movement in art and literature . Romancism was a reacrion against the Enlightenment’s embrace of rationality and reason . The Romantics emphasized emotion over rationality , and thought people should feel awe and terror in regard to nature . Frankenstein incorporates all these ideas. To Shelley , Frankenstein doesn’t fear and respect the world of nature enough ------she says that by tempering with nature , he brings about complete disaster . Frankenstein is not just a great Romantic novel . It’s also considered one of the first major works of science fiction . It influences a whole generation of writers , and the monster has become one of the most recognizable figures in Western culture.56. Which of the following is closest in the meaning to ‘hideous’ in Paragraph 1?A. UnattractiveB. EngagingC. CharmingD. Handsome57. What is Victor Frankenstein’s fatal weakness?A. His love of scienceB. His rejection of his own creationC. His lack of respect for natureD. His inability to form human relationship58. How was the Romantic era different from the Enlightenment ?A. The Romantic era emphasized emotion ; the Enlightenment emphasized reason .B. The Romantic era occurred during the 20th century ; the Enlightenment occurred during the 19th century .C. The Romantic era emphasized poetry ; the Enlightenment emphasized prose .D. The Romantic era saw major scientific discoveries ; the Enlightenment was an era of literary discovery .59. What effect did “ F rankenstein” have on later works of fiction ?A. It inspired books about the EnlightenmentB. It inspired technical writingC. It inspired books of poetryD. It inspired science-fiction writing60. If you are a 22-year-old nurse , you can apply for the railcard without ________.A. the signature of your director B $ 28c. application form D. passport-sized photos61. The 1/3 OFF discount may not apply for the railcard holders who travel at _______.A. 11 pm on Sunday in AugustB. 7. am on Tuesday in FebruaryC. 7 am on Monday in JulyD. 11 pm on Friday in March62. Which of the following is True according to the leaflet ?A. If you railcard doesn’t have your name signed , it will be used by someone else.B. The benefits of a railcard are transferable to your friend of your age .C. If you have no ticket but have boarded a train , you will still be eligible for a discounted ticketD. If railcard holders wish to use the Eurostar network , they must pay the full fare.The ‘ Phone Stack(堆)’GameWhenever Michael Carl , the fashion market director at Vanity Fair , goes out to dinner with friends , he plays something, called the “ phone stack” game : Everyone places their phones in the middle of the table ; whoever looks at their device before the check arrives picks up the bill . As smartphones continue to burrow(钻入) their way into our lives , and wearable devices like Google Glass threaten to eat into our person space even further , overburdened users are carving out their own device-free zones with special tricks and life hacks .“Disconnecting is a luxury that we all need ,” Lesley M. M. Blume , a Ne w York writer keeps her phone away from the dinner table at home .” The expectation that we must always be available to employers ,colleague, family : It creates a real obstacle in trying to set aside private time . But that private time is more important than ever. “ Much of the digital detoxing （戒毒）is centered on the home , where urgent e-mails from co-workers , texts from friends , Instagram photos from acquaintances and updates on Facebook get together to disturb domestic quietness.A popular method is to appoint a kind of cellphone lockbox , like the milk tin that Brandon Holley , the former editor of lucky magazine , uses. “ If my phones is buzzing or lighting up , it’s still a distraction , so it goes in the box . “, said Ms. Holley , who lives in a r ow house in Red Hook , Brooklyn , with her son ,Smith , and husband , John .” It’s not something I want my kid to see.” Sleep is a big factor , which is why some people draw the cellphone-free line at the bedroom.” I don’t want to sleep next to something t hat is a charged ball of information with photos an e-mails ,” said Peter Som , the fashion designer , who keeps his phone plugged in the living room overnight .” “It definitely is a head clearer and describes daytime and sleep time clearly .”Households with young children are especially mindful about being overconnected , with parents sensitive to how children may imitate bad habits . But it’s not just inside the home where users are separating themselves from the habit . Cellphone overusers are making efforts to disconnect in social settings ,whether at the request of the host or in the form of friendly competition . The phone-stack game is a lighthearted way for friends to police against rude behavior when eating out . The game gained popularity after Brian Perez, a dancer in Los Angeles , posted the idea online.63. What might be the reason for Michael Carl to play the “ phone stack” game?A. His friends aren’t willing to pay for the meal voluntarily .B. He wants to do some funny things with those phonesC. He has been fed up with digital devices being present everywhereD. The wearable devices have brought threats to his privacy .64.Why is it difficulty for people to break away from their digital device at home ?A. Because they have to do some work at homeB. Because they are expected to be always available to the outsideC. Because people have been addicted to digital devices.D. Because digital devices can enrich people’s family life.65. What does Peter Som do to ensure his sleeping quality at night ?A. He puts his phone in the living room .B. He ignores any information in the phoneC. He deletes all information in his phoneD. He puts his phones in a lockbox66. Why does the phone-stack game become popular as soon as it is posted online?A. The game helps create a harmonious relationship among friends.B. The game makes the host get along well with the guestC. The game can prevent children from imitating their parents’ behaviorD. The game meets people’s demand for keeping away from phones easilySection CDirections: Read the following passage. Fill in each blank with a proper sentence given in the box. Each sentence can be used only once. Note that there are two more sentences than you need.“Any apple today ?”, Effie asked cheerfully at my window ,. I followed her to her truck and bought a kilo . On credit , of course . Cash was the one thing in the world I lacked just them .All pretense （借口）of payment was drooped when our funds , food and fuel decreased to alarming lows. Effie came often , always bringing some gift: a jar of peaches or some firewood . There were other generosities.___________Effie was not a rich woman . Her income , derived from investment she had made while running an interior decorating shop , had never exceeded $200 a month , which she supplemented by selling her apples .But she always managed to help someone poorer .Years passed before I was able to return the money Effie had given me from time to time . She was ill now and had aged rapidly in the last year .” Here , darling , “ I said , “ is what I owe you ,” _____________” Give it back as I gave it to you -----a little at a time.” “ I think she believed there was magic in the slow discharge of a love debt.The simple fact is that I never repaid the whole amount to Effie , for she died a few weeks later . By now , the few dollars Effie gave me have been multiplied many times . But a curious thing began to happen .___________At that time , it seemed that my debt would forever go unsettled . So the account can never be marked closed , for Effie’s love will go on in hearts that have never known her .IV. Summary WritingDirections:Read the following passage. Summarize the main idea and the main point(s) of the passage in no more than 60 words. Use your own words as far as possible.Chaco Great HouseAs early as the twelfth century A.D., the settlements of Chaco Canyon in New Mexico in the American Southwest were notable for their "great houses," massive stone buildings that contain hundreds of rooms and often stand three or four stories high. Archaeologists have been trying to determine how the buildings were used. Whilethere is still no universally agreed upon explanation, there are three competing theories.One theory holds that the Chaco structures were purely residential, with each housing hundreds of people. Supporters of this theory have interpreted Chaco great houses as earlier versions of the architecture seen in more recent Southwest societies. In particular, the Chaco houses appear strikingly similar to the large, well-known "apartment buildings" at Taos, New Mexico, in which many people have been living for centuries.A second theory contends that the Chaco structures were usedto store food supplies. One of the main crops of the Chaco people was grain maize, which could be stored for long periods of time without spoiling and could serve as a long-lasting supply of food. The supplies of maize had to be stored somewhere, and the size of the great houses would make them very suitable for the purpose.A third theory proposes that houses were used as ceremonial centers. Close to one house, called Pueblo Alto, archaeologists identified an enormous mound formed by a pile of old material. Excavations of the mound revealed deposits containing a surprisingly large number of broken pots. This finding has been interpreted as evidence that people gathered at Pueblo Alto for special ceremonies. At the ceremonies, they ate festive meals and then discarded the pots in which the meals had been prepared or served. Such ceremonies have been documented for other Native American cultures.V. TranslationDirections: Translate the following sentences into English, using the words given in the brackets.72. 想和我一起看电影的人请举手。

上海市普陀区高三下学期物理质量调研(二模)试卷解析版

高三下学期物理质量调研〔二模)试卷一、单项选择题1.可见光属于〔〕A. 电磁波B. 次声波C. 超声波D. 机械波2.在天然放射现象中，放出的三种射线里有一种射线是带正电的。

组成这种射线的是〔〕A. 质子B. 中子C. 电子D. 氦原子核3.当用一束紫外线照射锌板时，产生了光电效应，这时〔〕A. 锌板带负电B. 有正离子从锌板逸出C. 有电子从锌板逸出D. 锌板会吸附空气中的正离子4..在“用单摆测定重力加速度〞的实验中，要用铁夹夹住摆线，这样做的主要目的是〔〕A. 便于测量单摆摆长B. 便于测量单摆周期C. 确保摆动时摆长不变D. 确保摆球在竖直平面内摆动5.用两节干电池串联后接在额定电压为2.5V 的小灯两端，小灯正常发光。

现将一节如下列图的方块电池接在该小灯两端，闭合电键后发现小灯亮度变暗，产生这一现象的主要原因是〔〕A. 方块电池的电动势过低B. 导线分担了大局部电压C. 小灯的电阻太大D. 方块电池的内阻太大6.如图为波源O 传出的一列水波，相邻实线间的距离等于一个波长以下说法正确的选项是〔〕A. 波通过孔A，发生明显的衍射现象B. 波通过孔B，不发生衍射现象C. 波遇到障碍物C，发生明显的衍射现象D. 波遇到障碍物D，不发生衍射现象7.如图，电路中电源电动势为E、内电阻为r，R0为定值电阻。

当滑动变阻器R 的滑片向a 移动时，以下说法正确的选项是〔〕A. R 两端的电压变大B. 流经R0的电流变大C. 电源总功率变小D. 电源内部消耗功率变大8.物体在竖直方向上分别做匀速上升、加速上升和减速上升三种运动。

以下说法正确的选项是〔〕A. 匀速上升机械能不变B. 加速上升机械能增加C. 减速上升机械能一定减小D. 上升过程机械能一定增加9.如图，在水平桌面上放置一张白纸，用杯子压住白纸。

现向右轻轻拉白纸，白纸未被拉动。

以下说法正确的选项是〔〕A. 杯子受到向右的摩擦力B. 杯子受到向左的摩擦力C. 桌面受到向右的摩擦力D. 桌面受到向左的摩擦力10.如图，当轿车以18km/h 的速度匀速驶入高速公路ETC 收费通道时，ETC 天线完成对车载电子标签的识别后发出“滴〞的一声。

2017上海物理水平等级考(含答案).doc

2017 年上海市普通高中学业水平等级性考试物理试卷一、选择题（共40 分。

第 1-8 小题，每小题 3 分，第 9-12 小题，每小题 4 分。

每小题只有一个正确答案。

）1.由放射性元素放出的氦核流被称为（A ）阴极射线（B）α射线（C）β射线（D）γ射线2.光子的能量与其（A ）频率成正比（B）波长成正比（C）速度成正比（D）速度平方成正比3.在同位素氢、氘，氚的核内具有相同的（A ）核子数（B）电子数（C）中子数（D）质子数4.用单色光照射位于竖直平面内的肥皂液薄膜，所观察到的干涉条纹为（ A）（B）（C）（D）5.如图，在匀强电场中，悬线一端固定于地面，另一端拉住一个带电小球，使之处于静止状态。

忽略空气阻力，当悬线断裂后，小球将做（A ）曲线运动（B ）匀速直线运动（C）匀加速直线运动（D ）变加速直线运动6.一碗水置于火车车厢内的水平桌面上。

当火车向右做匀减速运动时，水面形状接近于图7.从大型加速器射出的电子束总能量约为500GeV （1GeV ＝ 1.6 ×10-10J），此能量最接近（A ）一只爬行的蜗牛的动能（B）一个奔跑的孩子的动能（C）一辆行驶的轿车的动能（D）一架飞行的客机的动能8.一个密闭容器由固定导热板分隔为体积相同的两部分，分别装有质量不等的同种气体。

当两部分气体稳定后，它们的（A ）密度相同（B）分子数相同（C）分子平均速率相同（D）分子间平均距离相同9.将四个定值电阻a、b、 c、 d 分别接入电路，测得相应的电流、电压值如图所示。

其中阻值最接近的两个电阻是（A ） a 和 b（B）b和 d（C） a 和 c（D）c和 d10.做简谐运动的单摆，其摆长不变，若摆球的质量增加为原来的2的速度减为原来的 3，则单摆振动的（A ）周期不变，振幅不变（B）周期不变，振幅变小（C）周期改变，振幅不变（D）周期改变，振幅变大94倍，摆球经过平衡位置11.如图，一导体棒ab 静止在 U 型铁芯的两臂之间。

普陀区2017学年第二学期高三质量调研物理试卷(二模)

普陀区2017学年第二学期高三质量调研物理试卷一、选择题（共40分。

第1-8小题，每小题3分，第9-12小题，每小题4分。

每小题只有一个正确答案。

）1、由核反应产生，且属于电磁波的射线是（）（A）α射线（B）γ射线（C）X射线（D）阴极射线2、一颗恒星的寿命取决于它的（）（A）温度（B）颜色（C）质量（D）体积3、白光通过双缝后产生的干涉条纹是彩色的，其原因是不同色光的（）（A）频率不同（B）强度不同（C）振动方向不同（D）传播速度不同4、关于布朗运动，下列说法中正确的是（）（A）液体分子的无规则运动就是布朗运动（B）布朗运动的激烈程度跟温度无关（C）布朗运动是悬浮在液体中的固体颗粒不断地受到液体分子的撞击而引起的（D）悬浮在液体中固体颗粒越大，在某一瞬时撞击它的分子数越多，布朗运动越明显5、某教室墙上有一朝南的钢窗，当把钢窗左侧向外推开时，下列说法正确的是（）（A）穿过窗户的地磁场的磁通量变大（B）穿过窗户的地磁场的磁通量不变（C）从推窗人的角度看，窗框中的感应电流方向是逆时针（D）从推窗人的角度看，窗框中的感应电流方向是顺时针6、如图，倾斜的天花板上有一物块，该物块在竖直向上的恒力F作用下恰好能沿天花板匀速上升，下列说法中正确的是（）（A）物块一定受两个力的作用（B）物块一定受三个力的作用（C）物块可能受三个力的作用（D）物块可能受四个力的作用7、如图，在点电荷产生的电场中，实线MN是一条方向未标出的电场线，虚线AB是一个电子只在静电力作用下的运动轨迹。

下列说法正确的是（）（A）电子一定从A向B运动（B）A点电势高于B点电势（C）电子在A点的电势能大于它在B点的电势能（D）电子在A点的加速度大于它在B点的加速度8、如图，弹性轻绳的一端套在手指上，另一端与弹力球连接，用手将弹力球以某一竖直向下的初速度抛出，抛出后手保持不动。

从球抛出瞬间至球第一次到达最低点的过程中（弹性轻绳始终在弹性限度内，不计空气阻力），下列说法正确的是（）（A）绳刚伸直时，球的速度最大（B）该过程中，球的加速度一直减小（C）该过程中，重力对球做的功大于球克服绳的拉力做的功（D）在最低点时，球、绳和地球组成的系统势能最大9、甲、乙两同学们利用反应尺估测反应时间。

2017年上海等级考物理试题解析(解析版)

2017 年上海市普通高中学业水平等级性考试物理试题解析考生注意： 1．试卷满分 100 分，考试时间 60 分钟。

2．本考试分设试卷和答题纸。

试卷包括三部分，第一部分为选择题，第二部分为填空题，第三部分为综台题。

3．答题前，务必在答题纸上填写姓名、报名号、考场号和座位号，并将核对后的条形码贴在指定位置上。

作答必须涂或写在答题纸上，在试卷上作答一律不得分。

第一部分的作答必须涂在答题纸上相应的区域，第二、三部分的作答必须写在答题纸上与试卷题号对应的位置。

一、选择题（共 40 分。

第 1-8 小题，每小题 3 分，第 9-12 小题，每小题 4 分。

每小题只有一个正确答案。

）1．由放射性元素放出的氦核流被称为（）（A ）阴极射线（B ）α 射线（C ）β 射线（D ）γ 射线【答案】1. B【解析】氦核是α粒子。

2．光子的能量与其（）（A ）频率成正比（B ）波长成正比（C ）速度成正比（D ）速度平方成正比【答案】2. A【解析】普朗克公式νεh =，ν为频率。

3．在同位素氢、氘，氚的核内具有相同的（）（A ）核子数（B ）电子数（C ）中子数（D ）质子数【答案】3. D【解析】同位素具有相同的质子数，在元素周期表中处于同一位置。

【答案】 4. B【解析】由于重力作用，肥皂液薄膜从上到下依次变厚，所以干涉条纹为横，B 正确。

5．如图，在匀强电场中，悬线一端固定于地面，另一端拉住一个带电小球，使之处于静止状态。

忽略空气阻力，当悬线断裂后，小球将做（）（A ）曲线运动（B ）匀速直线运动（C ）匀加速直线运动（D ）变加速直线运动（A ）（B ）（C ）（D ）【答案】5.C【解析】带电小球受重力和电场力，合力是恒力，所以做匀加速直线运动。

6．一碗水置于火车车厢内的水平桌面上。

当火车向右做匀减速运动时，水面形状接近于图（）v v v v（A）（B）（C）（D）【答案】6. A【解析】加速度向后，所以合力向后，A图支持力向后上，重力向下，合力向后。

上海市普陀区2017届高三下学期质量调研物理试题 Word版含解析

单项选择题1. 温度较低的恒星，在天空中呈现（）A. 暗红色B. 黄色C. 白色D. 蓝色【答案】A【解析】恒星的颜色是由温度决定的，温度越低，颜色越偏红，温度越高，颜色越偏蓝．故天空中呈现暗红色，故A正确，BCD错误。

2. 人类认识到原子核的结构是复杂的，是从发现下列哪一现象开始的（）A. 阴极射线B. 光电效应C. 天然放射性现象D. 发现质子【答案】C【解析】许多元素能自发地放出射线，使人们开始认识到原子是有复杂结构的，即天然放射现象，故C正确，ABD错误.3. A. B两个点电荷间的距离保持恒定，当其他一些电荷被移近时，A、B间的库仑力将（）A. 变大B. 变小C. 不变D. 都有可能【答案】C【解析】根据可知，AB间电荷的库仑力与其他电荷是否存在无关，故C正确，ABD 错误。

4. 用点光源照射一个不透光的障碍物，其背后屏上阴影的中央出现了亮斑，原因是（）A. 光的反射B. 光的衍射C. 光的折射D. 光的干涉【答案】B【解析】光屏上影的中心会出现一个亮斑，这是光的衍射现象，故B正确，ACD错误。

5. 如图，一个环形电流的中心有一根通电直导线，则环受到的磁场力（）A. 沿环半径向外B. 沿环半径向内C. 沿水平向左D. 等于零【答案】D【解析】通电直导线产生的磁场是以导线上各点为圆心的同心圆，而环形电流的的方向与磁场方向平行，即B平行I，所以通电圆环不受安培力的作用，即F=0，故D正确，ABC错误。

6. 物体的温度升高，则（）A. 物体每个分子无规则运动的动能都增大B. 物体分子无规则运动的平均动能增大C. 物体一定从外吸热D. 物体运动的动能一定增大【答案】B所以B正确，ACD错误。

7. 如图为甲、乙两质点同时沿同一直线运动的位移-时间图像。

关于两质点的运动情况，下列说法正确的是（）A. 在0～t0时间内，甲、乙的运动方向相同B. 在0～2t0时间内，甲的速度一直在减小C. 在0～t0时间内，乙的速度一直增大D. 在0～2t0时间内，甲、乙发生的位移不相同【答案】D【解析】根据斜率表示速度可知，在0～t0时间内，甲的速度为负，乙的速度为正，说明甲、乙的运动方向相反，故A错误；根据斜率表示速度，可知在0～2t0时间内，甲的速度不变，故B错误；根据斜率表示速度，可知在0～t0时间内，乙的速度在减小，故C错误；在0～2t0时间内，甲的位移x1=-2x0，乙的位移为x1=2x0，大小相等，方向不同，位移不等，故D正确。

2017届上海市闵行区高三下学期质量调研考试物理试题(解析版)

第I卷（共40分）一、单选题（共40分，每题有且只有一个正确答案，1-8题每题3分，9-12题每题4分）1. 月球的存在对地球的潮汐现象产生影响，若地球和月球的关系如图所示时，高潮的位置是（）A. 仅A处B. 仅B处C. A和B处D. C和D处【答案】C2. 关于天然放射线性质的说法正确的是（）A. γ射线就是中子流B. α射线有较强的穿透性C. β射线是高速电子流D. 电离本领最强的是γ射线【答案】C【解析】射线是不带电的光子流，射线是电子流，故A错误C正确；三种射线的贯穿本领依次增强，三种射线的电离本领依次减弱，故BD错误；3. 关于电磁波，下列说法正确的是（）A. 电磁波在真空中的传播速度与电磁波的频率有关B. 周期性变化的电场和磁场可以相互激发，形成电磁波C. 电磁波在传播过程中可以发生干涉、衍射，但不能发生反射和折射D. 利用电磁波传递信号可以实现无线通信，但电磁波不能通过电缆、光缆传输【答案】B【解析】电磁波在真空中的传播速度恒为，A错误；根据麦克斯韦电磁理论可得周期性变化的电场和磁场可以相互激发，形成电磁波，B正确；电磁波也是波的一种，具有波的一切特性，可以发生反射和折射，C错误；电磁波可以在介质中传播，所以可以根据电缆、光缆进行有线传播，也可以不需要介质进行传播，即无线传播，D错误．4. 在“用油膜法估测分子的大小”实验中，用a ml纯油酸配制成b ml的油酸酒精溶液，现已测得一滴溶液c ml，将一滴溶液滴入水中，油膜充分展开后面积为S cm2，估算油酸分子的直径大小为（）A. B. C. D.【答案】A【解析】纯油酸体积为，油膜面积为S，油酸分子直径，故A正确．5. 为了尽量减少地磁场对实验现象的影响，在做奥斯特实验时（）A. 必须在地球赤道上进行B. 通电直导线应该沿南北方向水平放置C. 通电直导线应该沿东西方向水平放置D. 通电直导线必须竖直放置【答案】B6. 质点以加速度a做匀变速直线运动，经过一段时间t，质点的速度为v t，速度的改变量为Δv，则（）A. a越大v t也越大B. a越大Δv可能越小C. a与Δv方向一定相同D. a与Δv方向一定相反【答案】C【解析】加速度是描述速度变化快慢的物理量，与末速度的大小无关，A错误；根据知，加速度越大，两者的比值大，但速度变化量不一定小，B错误；根据知，加速度越大，时间一定时，速度变化量越大，故C正确；加速度的方向与速度变化量的方向相同，D错误．7. 如图所示，一个闭合导体圆环固定在水平桌面上，一根条形磁铁沿圆环的轴线运动，使圆环内产生了感应电流。

2017上海物理水平等级考+答案

2017年上海市普通高中学业水平等级性考试物理试卷考生注意：1．试卷满分100分，考试时间60分钟。

2．本考试分设试卷和答题纸。

试卷包括三部分，第一部分为选择题，第二部分为填空题，第三部分为综台题。

3．答题前，务必在答题纸上填写姓名、报名号、考场号和座位号，并将核对后的条形码贴在指定位置上。

作答必须涂或写在答题纸上，在试卷上作答一律不得分。

第一部分的作答必须涂在答题纸上相应的区域，第二、三部分的作答必须写在答题纸上与试卷题号对应的位置。

一、选择题（共40分。

第1-8小题，每小题3分，第9-12小题，每小题4分。

每小题只有一个正确答案。

）1．由放射性元素放出的氦核流被称为（）（A）阴极射线（B）α射线（C）β射线（D）γ射线2．光子的能量与其（）（A）频率成正比（B）波长成正比（C）速度成正比（D）速度平方成正比3．在同位素氢、氘，氚的核内具有相同的（）（A）核子数（B）电子数（C）中子数（D）质子数（A）（B）（C）（D）5．如图，在匀强电场中，悬线一端固定于地面，另一端拉住一个带电小球，使之处于静止状态。

2017上海物理水平等级考含答案

2017年上海市普通高中学业水平等级性考试物理试卷一、选择题（共40分。

第1-8小题，每小题3分，第9-12小题，每小题4分。

每小题只有一个正确答案。

）1.由放射性元素放岀的氦核流被称为（A）阴极射线（B）a射线（C）B射线（D ）丫射线2.光子的能量与其）频率成正比（B）波长成正比（A （C）速度成正比D）速度平方成正比（3.在同位素氢、氘，氚的核内具有相同的（A）核子数（B）电子数（C）中子数（D）质子数4.用单色光照射位于竖直平面内的肥皂液薄膜，所观察到的干涉条纹为UD) ( C) ( ((A) B)如图，在匀强电场中，悬线一端固定于地面，另一端拉住一个带电小球, 使之处于静止状5.态。

（A ）曲线运动 B ）匀速直线运动（）匀加速直线运动（C D ）变加速直线运动（ 6.—碗水置于火车车厢内的水平桌面上。

当火车向右做匀减速运动时，水面形状接近于图7.从大型加速器射岀的电子束总能量约为 500GeV （1GeV =1.6 x 10-10J ）,此能量最接近（A ）一只爬行的蜗牛的动能（B ）一个奔跑的孩子的动能（D ）一架飞行的客机的动能）一辆行驶的轿车的动能（ C8. —个密闭容器由固定导热板分隔为体积相同的两部分，分别装有质量不等的同种气体。

当两部分气体稳定后，它们的（A ）密度相同（B ）分子数相同（D ）分子间平均距离相同（C ）分子平均速率相同9. 将四个定值电阻 a 、b 、c 、d 分别接入电路，测得相应的电流、电压值如图所示。

其中阻值最7a a■ ■t ） c ■I ■接近的两个电阻是°Jd b 和（BA ） a 和 b ）（d c 和（C （） a 和 c D ）9倍，摆球经过平衡位置做简谐运动的单摆，其摆长不变，若摆球的质量增加为原来的 10•- 42的速度减为原来的，则单摆振动的3 （B ）周期不变，振幅变小（A ）周期不变，振幅不变）周期改变，振幅变大 D C （）周期改变，振幅不变（型铁芯的两臂之间。

《解析》上海市2017届高三下学期期中模拟调研考试物理试题Word版含解析

上海市2017届高三下学期期中模拟调研考试物理试题一. 选择题（共40分，1-8题每题3分，9-12题每题4分。

每题只有一个正确选项）1. 下列物理量中属于标量的是（）A. 路程B. 力C. 电场强度D. 加速度【答案】A【解析】A、标量是只有大小没有方向的物理量，路程是标量，故A正确；BCD、矢量是既有大小又有方向的物理量，电场强度、加速度和力都是矢量，故BCD错误。

点睛：对于矢量与标量，要掌握它的两大区别：一是矢量有方向，标量没有方向；二是运算法则不同，矢量运算遵守平行四边形定则，标量运算遵守代数加减法则。

2. 下列情景中，物体M所受摩擦力f的示意图正确的是（）【答案】B考点：摩擦力产生条件和方向。

3. 下列关于物理思想方法或概念的说法正确的是（）A. 伽利略的斜面理想实验是采用了“猜想-假设-证明”的物理归纳法得出结论的B. 卡迪文许是世界物理学史上第一个利用扭秤实验精确测量出了静电力k的常量C. 研究共点力合成的实验从力的等效性出发，利用到了等效替代的物理思想方法D. 重力加速度g是由地球对地球表面上的物体吸引而产生的，g的大小是定值10【答案】C【解析】A、在伽利略研究力与运动的关系时，是在斜面实验的基础上，成功地设计了理想斜面实验，他以实际的实验为依据，抓住了客观事实的主要因素，忽略了次要因素，从而能够更深刻地揭示了自然规律．因此，理想实验是实际实验的延伸，而不是实际的实验，是建立在实际事实基础上的合乎逻辑的科学推断，故A错误；B、卡文迪许通过扭秤实验测量了引力常量G，并验证了万有引力定律，而不是静电力常量k，故B错误；C、在探究共点力的合成时用到了等效替代的思想方法，故C正确；D、重力加速度g的大小地理位置有关，在地球上不同的地方，重力加速度g的大小一般是不同的，故D错误。

点睛：解决本题的关键要掌握记牢物理学史，同时伽利略的“理想斜面实验”是建立在可靠的事实基础之上的，它来源于实践，而又高于实践，它是实践和思维的结晶。

上海市普陀区高三物理下学期质量调研试题

高三质量调研物理卷注意事项：1. 本试卷分第I卷和第II卷。

满分150分。

考试时间120分钟。

2. 本试卷g取10m/s2。

sin370=0.6，cos370=0.8。

3. 请将答案填写在答题卡上。

第I卷(共56分)一、单项选择题（共16分，每题2分，每题只有一个正确选项）1．元电荷是指（A）电子（B）质子（C）中子（D）自然界中已知的最小电荷量2．下列属于原子核裂变的链式反应的是（A）核电站发电（B）氢弹爆炸（C）石油的形成（D）利用太阳能发电3．在杨氏双缝实验中，若两缝之间的距离稍为加大，其他条件不变，则干涉条纹将（A）变密（B）变疏（C）不变（D）消失4．用单色光通过小圆盘和小圆孔做衍射实验时，在光屏上得到衍射图形，它们的特征是（A）中央均为亮点的同心圆形条纹（B）中央均为暗点的同心圆形条纹（C）用小圆盘时中央是暗的，用小圆孔时中央是亮的（D）用小圆盘时中央是亮的，用小圆孔时中央是暗的5．下列说法正确的是（A）气体温度升高，则每个气体分子的动能都将变大（B）分子间距离增大时，分子间的引力和斥力都增大（C）气体的压强是由于大量分子频繁撞击器壁产生的（D）一定质量理想气体的温度升高，内能不一定增大6．在α粒子散射实验中，我们并没有考虑到α粒子跟电子碰撞，这是因为（A）电子体积非常小，以至于α粒子碰不到它（B）电子质量远比α粒子的小，所以它对α粒子运动的影响极其微小（C）α粒子跟各个电子碰撞的效果相互抵消（D）电子在核外均匀分布，所以α粒子受到电子作用的合外力为零7．如图为含逻辑电路的一个简单电路图，L为小灯泡。

光照射光敏电阻时，其阻值R′将变得远小于R。

当光照射光敏电阻时，则（A）R两端的电势差变小（B）R′两端的电势差变大（C）小灯泡L发光（D）小灯泡L不发光8．现有一台落地电风扇放在水平地面上，该电风扇运行时，调节它的“摇头”旋钮可改变风向，但风向一直水平。

若电风扇在地面上不发生移动，下列说法正确的是（A）电风扇受到5个力的作用（B）地面对电风扇的摩擦力的大小和方向都不变（C）空气对风扇的作用力与地面对风扇的摩擦力大小相等（D）风扇对空气的作用力与地面对风扇的摩擦力互相平衡二、单项选择题（共24分，每小题3分，每小题只有一个正确选项）9．某放射性元素的原子核发生两次α衰变和六次β衰变，关于它的原子核的变化，下列说法中正确的是（A）中子数减小8 （B）质子数减小2 （C）质子数增加2 （D）核子数减小1010．如图，站在向右作匀加速直线运动的车厢内的人向前推车壁，下列说法正确的是（A）人对车的作用力仅是手的推力（B）车对人的摩擦力大于车对人的推力（C）因为人相对车没有动，所以合外力为零（D）该人对车做正功11．如图为安检门原理图，左边门框中有一通电线圈，右边门框中有一接收线圈。

2. 答案

普陀区2017学年第二第二学期高三质量调研物理答案一、单项选择题（共40分。

第1-8小题，每小题3分，第9-12小题，每小题4分。

每小题只有一个正确答案。

）题号 1 2 3 4 5 6 7 8 答案 BC A C CD B D 题号 910 11 12 答案B BC A二、填空题（共20分。

本大题有5小题，每小题4分，每空格2分。

）题号答案 13整数，基元电荷 14质子， 153， 4/3 162p 0 ， p 0S /g 17 垂直ab 连线斜向下，10√2/π三、综合题18. （12分）（1）（A ）（D ）（G ）（3分）（2）（C ）（3分）（3）木板倾角α和单摆振动的周期T ； T 2，1/（g sin α）（填其他合理答案也给分）（6分）19. （12分）解：（1）小球从A 点释放滑至B 点，只有重力做功，机械能守恒：2122=210 1.25/5/B B mgR mv v gR m s m s===⨯⨯=（3分）（2）小环刚要到B 点时，处于圆周运动过程中，222215/20/1.25B v a m s m s R === （2分）加速度方向沿B 点半径指向圆心（1分）（3）小环过B 点后继续滑动到停止，可看做匀减速直线运动：2222222220.2,0.20.210/2/5112.5,2 2.5 6.25222B mg ma a g m s m s v t s s s a t m m a ===⨯======⨯⨯=（6分）20. （16分）解：（1）由安培定则、右手定则可以判定，cd 杆中感应电流方向沿+y 方向；（2分）0000(2)(12)(12)kI v B x v I R xR IR x v kI ==++= （3分）（2）由上式，取连续相等两位移x ∆，cd 杆经过两段位移速度变化量v ∆相同，但由于cd 杆加速滑动，故后一段位移时间t ∆比前一段短，由v a t∆=∆，可知杆的加速增大；（3分）（3）t 秒末，cd 杆在两导轨之间的一段两端电压： 10(22)U I x R =；杆伸出导轨外部分两端电压：20(2)(12)(2)U B L x v IR L x =-=+-所以，cd 杆两端电压：120[(12)2]U U U L x IR =+=+-（4分）（4）cd 杆受到的安培力: 0(2)2A F BI x kI I ==cd 杆在t 秒内，克服安培力的功等于闭合回路中产生的总焦耳热：002A A W F x kI Ix Q ===00000212222(21)12Q Q Q xR Q Q xR Q Q kI Ix'=+=='==-+（4分）。