高二寒假作业
高二化学寒假作业(二)

高二化学寒假作业(二)一.选择题(共7小题,每个小题只有一个正确选项)OH4.在1.0L密闭容器中放入0.10 mol X,在一定温度下发生反应:X(g)⇌Y(g)+Z(g)△H<0容器内气体总压强p随反应时间t的变化关系如图所示.以下分析正确的是()5.在体积一定的密闭容器中给定物质A、B、C的量,在一定条件下发生反应建立的化学平衡:aA(g)+bB(g)xC(g),符合下图甲所示的关系(C%表示平衡混合气中产物C的百分含量,T表示温度,p表示压强).则图乙中y轴是指()﹣14﹣137.2013年12月2日嫦娥三号月球探测器在西昌卫星发射中心成功,探测器使用被称为“软电池”的可充电电池.电池总反应的化学方程式为:Zn+2MnO2+H2O Zn(OH)2+Mn2O3,下列说法错误的是()二.填空题(共3小题)8.(1)已知某溶液中只存在OH﹣、H+、NH4+、Cl﹣四种离子,某同学推测其离子浓度大小顺序有以下几种:A.c(Cl﹣)>c(NH4+)>c(H+)>c(OH﹣)B.c(Cl﹣)>c(NH4+)>c(OH﹣)>c(H+)C.c(NH4+)>c(Cl﹣)>c(OH﹣)>c(H+)D.c(Cl﹣)>c(H+)>c(NH4+)>c(OH﹣)①上述关系一定不正确的是_________(填序号).②若溶液中只有一种溶质,则该溶液中离子浓度的大小关系为_________(填序号).③若四种离子浓度关系有c(NH4+)=c(Cl﹣),则该溶液显_________(填“酸性”、“碱性”或“中性”).(2)常温下,有A、B、C、D四种无色溶液,它们分别是CH3COONa溶液、NH4Cl溶液、盐酸和NaNO3溶液中的一种.已知A、B的水溶液中水的电离程度相同,A、C溶液的pH 相同.则:B是_________溶液,C是_________.(1)写出H2O2在催化剂作用下分解反应的化学方程式_________(2)从上表可以得出:活性炭、FeCl3、KI 和MnO2(粉末状)几种催化剂中,催化效率由大到小的顺序是_________,等质量的固体催化剂,颗粒大小对催化效率有什么影响_________(3)实验发现新鲜的动物肝脏对H2O2的分解也有显著的催化作用,但当往溶液中加入盐酸,或给溶液加热时,就会失去催化能力,合理的解释是_________(4)对于FeCl3的催化作用,有人认为是Fe3+起催化作用,有人认为是Cl﹣,请你设计一个实验进行验证._________.10.一定温度下在体积为5L的密闭容器中发生可逆反应.Ⅰ、若某可逆反应的化学平衡常数表达式为K=.(1)写出该反应的化学方程式:_________;(2)能判断该反应一定达到化学平衡状态的依据是_________(填选项编号).A.容器中气体的平均相对分子质量不随时间而变化B.v正(H2O)=v逆(H2)C.容器中气体的密度不随时间而变化D.容器中总的物质的量不随时间而变化E.消耗n mol H2的同时消耗n mol COⅡ、若该密闭容器中加入的是2mol Fe(s)与1mol H2O(g),t1秒时,H2的物质的量为0.20mol,到第t2秒时恰好达到平衡,此时H2的物质的量为0.35mol.(1)t1~t2这段时间内的化学反应速率v(H2)=_________mol/(L•S).(2)若继续加入2mol Fe(s),则平衡移动_________(填“向正反应方向”、“向逆反应方向”或“不”),继续通入1mol H2O(g)再次达到平衡后,H2的物质的量为_________mol.参考答案一选择题2)。
高二英语寒假作业(一)

太原市第二实验中学校2022-2023学年高二年级寒假作业英语(一)高二英语备课组一.用括号内单词的正确形式填空1. The president said it was a great opportunity to teach kids about the ________ (elect).2. I don't have anything ________ (suit) to wear for the coming of age party.3. He opened his lunch box and poured in the hot water, and then the delicious smell ______(instant) filled the air.4. ________ (library) are trained experts who can match the right book to the right teen, whether he or she is a struggling reader, an English language learner, or disabled.5. In ________(conclude), I would like to thank everyone who helped me to adapt to new school life.6. When you face a difficulty, just stand back and look ________(objective)at the problem at first.7. It would be crazy to spend so much money on expensive ________(item)such as world-famous brand bags and perfumes.8. You should be aware that how you manage your _______ (financial) can make a big impact on your future life.9. Taking time to ________ ( investment) in yourself can be one of the most profitable decisions you'll ever make.10. Though Anne is from one of the most remote ________(district) of the south of Scotland, she never gives up pursuing her dance dream.二.用方框内短语的适当形式填空1. You've got to ________________ yourself, or you'll never succeed.2. Johnny's friendliness was ________________ his brother's rude behaviour.3. Every week I ________________ a few pounds for a new smartphone.4. We want to ensure that help is ________________ for all children suffering from mental illness.5. Some people who live in the undeveloped regions of the world even ________________ clean water.6. After the disaster, we ________________ by donating money and they felt grateful for that.7. He tried to stay ________________ his emotions. However, it's easier said than done.8. Try to be in ________________, instead of focusing so much on what the future may bring.9. ________________ a credit card means you've reached your credit limit and no longer have additional credit to use that card.10.Have you decided to move the family to Alaska for a new job? Don't I _______ _______ ______ on the matter?I am a college student now!三.阅读理解AJust over a year ago, my iPhone was picked. My first thought was to replace it. But I stopped myself and asked a question: Does owning a smartphone make my life better, or worse? I decided to try living for a time without a smartphone. So I bought an old, $30 flip phone and began my post-smartphone life.One day after I made the switch, my wife, daughter and I were in Washington visiting a museum. By afternoon, I started acting like a true addict. I used my wife's smartphone to check Gmail. The initial rush of seeing so many unread emails was spoiled ( 破坏) by a work-related message. For the next half-hour or so, I walked around thinking about that message instead of being present at the museum. I was physically there, but my mind was focused on work.The most immediate advantage of not owning a smartphone, I quickly learned, is the ability to immerse( 沉浸) yourself in social situations. Without a smartphone to look at, you don't have much of a choice but to be present, and other people — whether it's a colleague ( 同事) or a stranger on social media — can't enter your life easily at inconvenient times. So I made my short-term experiment permanent.Do I miss Google Maps? Kind of, but I've also discovered that not having it makes driving safer. I now check a map before I leave the house and write down basic directions. This keeps me focused on the road rather than the phone. If I get lost, it's nice to ask people for directions. What about Uber and Lyft? Not having them has encouraged me to ride my bike more, which has been great for my health and saved me hundreds of dollars. On the subject of money: My phone bill is now down to $30 a month. I have no data plan, no expensive phone to make payments on, no apps to buy.1. Why did the author buy the old phone?A. To save money.B. To reduce the risk of losing it.C. To break his smartphone addiction.D. To experience a smartphone-free life.2. What happened to the author at the museum that afternoon?A. He couldn't help accessing the Internet.B. He couldn't send his work-related email.C. He was urged to handle work immediately.D. He was prevented from destroying a work of art.3. What is the last paragraph mainly about?A. The disadvantages of Google Maps.B. The functions of three different apps.C. The benefits of not using a smartphone.D. The difficulties of not having a smartphone.BWhen you think of a national park, you generally picture fresh air and wild animals, right? Well, now you're going to have to add tea shops and something called “the Underground” to your definition (定义), because London, England has signed up to be the first “National Park City.”London was founded by the Romans around 2, 000 years ago and people have continually lived there since then. In all that time, however, nobody had the idea to replace all the parks with big box stores or high buildings, which means London already has a much lower urban density (密度) than most of the world's cities. Nowadays about a third of the city is green space.In July 2019, London announced its willingness to become the world's first National Park City. Now the city is moving toward the goal of achieving 50% green space by the year 2050 by connecting and increasing public parks, greening unused parking lots and the private yards of existing and new houses, and fixing some green roofs on existing buildings.“Encouraged by the aims and values of our rural (乡村的) national parks, the London National Park City is basically about making life better in the capital through both small everyday things and long - term thinking,”Daniel Raven-Ellison, who began the movement to make London a National Park City six years ago, said. “We've been doing that in London for centuries, which is why London is so green.” It's about going further to make the city greener, healthier and wilder; making the city richer in wildlife.London will have a much easier job achieving this type of green transformation ( 转变 ) than more densely-urbanized cities like Paris and New York, which have 10% and 27% green space, respectively. But that doesn't mean it's not possible — the National Park City Foundation hopes to include 25 more cities in addition to London by the year 2025. Glasgow, Scotland and Newcastle upon Tyne in northeast England are both considering becoming National Park Cities.4. What makes London more likely to become a National Park City than other cities?A. Its smaller population.B. Its locals' requirements.C. Its government's strict law.D. Its wider area of green space.5. What does Daniel try to talk about in the fourth paragraph?A. The values of newly-founded parks.B. The importance of his movement.C. The influence of green space on cities.D. The preparation for setting up a movement.6. What would be the best title for the text?A. London is leading the world in park constructionB. London becomes the world's first National Park CityC. London is listed as the world's most-visited cityD. London has built the world's first underground parkCWhen someone asks me what I do first thing in the morning I feel ashamed. Then, I have to shamefully admit that I turn my alarm off on my phone and scroll (滚屏) through WeChat. Before I've even had the chance to brush my teeth or wash my face I'm already right away attracted by whatever people are doing online. And I know it needs to change.But the last time I was asked this question was about two months ago and have I changed my ways? Not even a little bit. We all know how unproductive social media can be. So why is it so easy to get addicted to (沉溺于) a huge mass of pretty pictures, and funny behavior and ideas? And why is it so hard to change? Lisa Lewis, a doctor in Brookline tells me the answer is simple. “It's because the point of these apps is to keep you looking,” she says. “They want you to buy, and get you to follow and like. Their only purpose is to win your attention.”She says you must have a purpose when it comes to using any social media apps. “Don't just go on and scroll,” she explains. “Just like you wouldn't walk up to the refrigera tor and stare at what's inside for no reason, don't do the same with social media.” If social media is reducing your productivity and overall health, Lewis offers these steps:First, set a goal whenever you use a social media app. If you use WeChat to get inspiration to exercise, do that and then get off it. Next, you can use a timer. These days you can set a timer for how many hours a day youspend on social media. Set it and stick to it. And finally, you can create a prize to strengthen the behavior. When you set that timer and stick to it, positively strengthen the behavior with anything from tasty food to things you've been eyeing on Amazon.7. What can we say about the author according to Paragraph 1?A. She is shy about answering others' questions online.B. She cares little about other people's life.C. She works busily early in the morning.D. She is a heavy user of social media.8. Why is it difficult to beat the addiction mentioned in Paragraph 2 according to Lewis?A. The apps are aimed at attracting users.B. Social media are a good way to kill time.C. People want to communicate with friends.D. Online information is key to most people's life.9. Why does Lewis mention the refrigerator?A. To show how attractive social media could be.B. To discuss why social media reduce productivity.C. To explain one should use social media when necessary.D. To prove some content of social media is useful.10. What does the underlined part “the behavior” refer to?A. Drawing inspiration from social media.B. Using social media according to a timer.C. Trying to save money when shopping online.D. Learning to pay no attention to things you badly want.DWhen is a kid not a kid anymore? If you asked my 12-year-old daughter, the magical age would be 13, when you can no longer be considered a “child.” If you asked my 15-year-old niece, the age would be 16, when she will be able to drive a car and get an after-school job. According to the U. S. government, a child officially becomes an adult when they turn 18. That's when they can vote. But even though an 18-year-old starts paying taxes, the government does not consider that person mature enough to buy a beer. Still, even a kid who can buy a beer is not old enough to rent a car.Scientists have learned from a new study that when kids are around 18, their prefrontal cortex, which helps control impulses ( 冲动), solve problems, and organize behavior, is only halfway developed. That's not to say that kids in their late teens and early 20s can't take on these tasks, but it means that it's harder for them to do so — at least until around age 25 or so when this area of the brain fully develops.“What we're really saying is that to have a definition (定义) of when you move from childhood to adulthood looks absurd,” Peter Jones from the University of Cambridge said. “It's a much more nuanced (微妙的) change that takes place over thirty years.”This isn't a news flash for parents who have watched their teens take crazy risks while seeming unable to get their lives together until they're older. But this information throws new light on the way kids without as much support are treated. In the foster (寄养的) care system, once a child turns 18, he can no longer receivestate-backed support. And many people think this is too early for a teen to be on his own, especially a teen who has experienced a painful childhood. Because of this, some foster care advocates (提倡者) think it makes more sense for 25 to be the new legal age of adulthood.11. What does the author want to show us in Paragraph 1?A. Different age groups have different needs.B. Becoming an adult means you can do a lot of things.C. People have different opinions on becoming an adult.D. Children need to learn basic life skills to become an adult.12. What might be the purpose of the study?A. To explain why teenagers are at risk.B. To suggest a way of helping teenagers develop.C. To explore the characteristics of different age groups.D. To discover when the human brain is fully developed.13. What does the underlined word “absurd” in Paragraph 3 probably mean?A. Impossible.B. Invaluable.C. Unreasonable.D. Uninteresting.14. What influence may the study have?A. It may inspire teens to be independent.B. It may allow a 20-year-old to get government support.C. It may drive the government to protect the foster care system.D. It may encourage parents to stop supporting their children at college.四.七选五The age of majority is the age that children become adults by law. This means that they are legally in control of their own actions and decisions. 1. ________ When used this way, the word “majority” means having the necessary number of years to be considered an adult. The opposite is “minority”, which means bein g a minor or child.2. ________ The law in a given place may never actually use the words “age of majority”. The age of majority is a legally fixed age and idea of adulthood which is different in different places. It may not match the actual maturity of a person's body or mind. The age of majority is 18 in most places.3. ________ Once a person reaches the age of majority, there are some things they can do that they could not do before. These may include voting, buying or drinking alcohol and driving cars on public roads. The ages when these things can be done are different.4. ________Even after a person reaches the age of majority, they cannot do whatever they want to immediately. 5.________ For example, the youngest a person is allowed to purchase alcohol is 21 in all U. S. states even though the age of majority is 18 in most states. The age of majority in the Republic of Ireland is 18, but a person must be over 21 years old to stand for election.五.完形填空You could say young Moziah Bridges has a gift for fashion, but it's more than that. He was born in Tennessee on November 13, 2001. When he was very young, he traded bow ties for candies in the school playground. However, Moziah's 1 fashion sense led him to home in on (集中精力于) his gift for 2 , and he started his own company at the age of 9. What he loved most were bow ties. But the 3 was that he felt that none of his bow ties attracted young people. Thus, the next step for Moziah was to 4 ties that are suitable for the young. He asked his grandmother to teach him how to sew ( 缝纫) and worked 5 to improve. As a result, Mo's Bowswas given to the world. The colorful, handmade ties quickly achieved 6 on major networks. When discussing his creativity and inspiration, Moziah said that designing a colorful bow tie was just part of his 7 of making the world a fun and happier place.The Mo's Bows website is sweet and it has started to sell other products, such as pocket squares and T-shirts. There's even a guide suggesting how to 8 tie a Mo's Bow, which is certainly something that men of all ages can 9 .Moziah is also best known for having 10 on the NBC reality TV series “Shark Tank” at the age of 11, increasing the 11 and popularity of his products and he has earned over $165,000 from his business. The designer owes (把……归功于) all of his 12 to h is grandmother, because, as Moziah says, “She13 me to be the best.”Recently, Moziah sold his Go Mo bow tie and 14 $1, 600 to give to Glenview Summer Camp. That money was enough to 15 the camp costs for 10 kids, and this is an activity Moziah hopes to make a tradition. Moziah's next plan is to help more people in need. This young man certainly has big things ahead!1. A. doubtful B. terrible C. strange D. strong2. A. staying up B. dressing up C. cleaning up D. cheering up3. A. reason B. worry C. problem D. plan4. A. predict B. collect C. accept D. create5. A. tirelessly B. carelessly C. helplessly D. hopelessly6. A. independence B. balance C. popularity D. protection7. A. story B. research C. dream D. training8. A. necessarily B. properly C. frequently D. completely9. A. get through B. work out C. throw away D. learn from10. A. appeared B. served C. grown D. checked11. A. flow B. quality C. costs D. sales12. A. politeness B. survival C. success D. gift13. A. follows B. considers C. advises D. pushes14. A. borrowed B. raised C. lost D. demanded15. A. reduce B. change C. cover D. increase六.语法填空The relationship between children and their parents is the most important one in a child's life, 1. ________ often lasts well into adulthood. This relationship changes 2. ________ (great) as teenagers need increased independence from their family. With increased independence comes the possibility of increased risk, and teens need parents to help them rise to the challenges that adolescence presents. Though some 3. ________ (argument) between teenagers and their parents are normal, teenagers still depend on parents to provide support and help.Just as close parent-child relationships are connected with the 4. ________ (health) development of teenagers, positive parenting behaviors are connected with increased parent-child closeness. Parenting a teenager differs 5.________ parenting a younger child. As children grow, parenting changes from making decisions for younger children to helping teenagers make decisions on 6. ________ (they) own. Parents can provide needed support 7.________ (help) their teenagers understand how their choices can influence their health and well-being. Although friends become more important in the lives of teenagers, 8. ________ (influence) their dressing styles, certain behaviors and social life, parents still play 9. ________ important role. They help shape their educational plans, social values and world view.Developing a positive and strong parent-teenager relationship 10. ________ (do) good to teenagers. Positive parent-child relationships contribute to higher levels of self-esteem (自尊), happiness and kindness, and also reduce their physical and mental pains.七.翻译句子1. 明年的这个时候,你正坐在办公室里和你的同事一起工作。
高二数学寒假作业

高二数学寒假作业篇一:高二数学假期作业(2)高二数学假期作业(2)第Ⅰ卷(选择题,共60分)一、选择题:本大题共12分,每小题5分,共60分.1.若函数f(某)在某=1处的导数为3,则f(某)的解析式可以为A.f(某)=(某-1)2+3(某-1)B.f(某)=2(某-1)C.f(某)=2(某-1)2D.f(某)=某-12.(某)10的展开式中某6y4项的系数是A.840B.-840C.210D.-2103.一个学生能够通过某种英语听力测试的概率是得通过的概率是A.,他连续测试2次,那么其中恰有一次获2D.14B.13C.12344.已知曲线y=co某,其中某∈[0,A.1B.23π],则该曲线与坐标轴围成的面积等于25C.D.325.一位母亲纪录了儿子39岁的身高的数据(略),她根据这些数据建立的身高y(cm)与年龄某的回归模型为y=7.19某+73.93,用这个模型预测这个孩子10岁时的身高,则正确的叙述是A.身高一定是145.83cmC.身高在145.83cm以上6.若复数B.身高在145.83cm左右D.身高在145.83cm以下a3i(a∈R,i为虚数单位)是纯虚数,则实数a的值为12iA.-2B.4C.-6D.67.若z∈C且|z+2-2i|=1,则|z-2-2i|的最小值等于A.2B.3C.4D.58.通过随机询问250名不同性别的大学生在购买食物时是否看营养说明书,得到如下2某2联A.95%以上认为无关B.90%95%认为有关C.95%99.9%认为有关D.99.9%以上认为有关9.从4位男教师和3位女教师中选出3位教师,派往郊区3所学校支教,每校1人,要求这3位教师中男、女教师都要有,则不同的选派方案有A.210种B.186种C.180种D.90种10.若A,B,C,D,E,F六个不同元素排成一列,要求A不排在两端,且B、C相邻,则不同的排法共有A.72种B.96种C.120种D.144种11.(某2+2某+1)d某=().A.4B.13C.12D.3412.从一副不含大小王的52张扑克牌中不放回地抽取2次,每次抽1张,已知第1次抽到A,那么第2次也抽到A的概率为().A.B.13C.12D.117第Ⅱ卷(非选择题,共74分)二、填空题:本大题共4小题,每小题4分,共16分,把答案填在答题卡指定位置上.13.在数列{an}中,a1=3,且an1=a2,则数列{an}的通项公式an=_____.n(n为正整数)14.若(2某-1)7=a7某7+a6某6+…+a1某+a0,则a7+a5+a3+a1=_____________.15.某信号兵用红、黄、蓝3面旗从上到下挂在竖直的旗杆上表示信号,每次可以任挂1面、2面或3面,并且不同的顺序表示不同的信号,一共可以表示___________种不同的信号.16.函数y=in3某+co3某在[-,]上的最大值是________________.44三、解答题:本大题共6小题,共74分,解答应写出文字说明、证明过程或演算步骤.17.(本小题满分12分)n2(n1)2用数学归纳法证明:当n为正整数时,1+2+3+……+n=.433318.(本小题满分12分)某年级的联欢会上设计了一个摸奖游戏,在一个不透明的口袋中装有10个红球和20个白球,这些球除颜色外完全相同,一次从中摸出5个球,至少摸到3个红球就中奖,求中奖概率.根据工资待遇的差异情况,你愿意选择哪家单位?请说明你的理由.20.(本小题满分12分)先阅读下面的文字,再按要求解答.如图,在一个田字形地块的A、B、C、D四个区域中栽种观赏植物,要求同一区域种同一种植物,相邻两区域(A与D,B与C不相邻)种不同的植物,现有四种不同的植物可供选择,问不同的种植方案有多少种?AB某学生给出如下的解答:CD解:完成四个区域种植植物这件事,可分4步,第一步:在区域A种植物,有C14种方法;第二步:在区域B种植与区域A不同的植物,有C13种方法第三步:在区域D种植与区域B不同的植物,有C13种方法第四步:在区域C种植与区域A、D均不同的植物,有C12种方法根据分步计数原理,共有C14C3C3C2=72(种)答:共有72种不同的种植方案.问题:(Ⅰ)请你判断上述的解答是否正确,并说明理由;(Ⅱ)请写出你解答本题的过程.为了研究不同的给药方式(口服与注射)和药的效果(有效与无效)是否有关,进行了相22.(本小题满分14分)已知函数f(某)=(某2-2某)ek某(k∈R,e为自然对数的底数)在(和∞)上递增,在[上递减.(Ⅰ)求实数k的值;(Ⅱ)求函数f(某)在区间[0,m]上的最大值和最小值.根据193个病人的数据,能否作出药的效果与给药方式有关的结论?请说明理由.高二数学假期作业(2)参考答案二、填空题:每小题4分,共16分.13.3214.109415.1516.1三、解答题:共74分.n1122217.证明:(1)当n=1时,左边=1,右边==1,4∴等式成立.································································································2分(2)假设当n=k时,等式成立,即k2(k1)21+2+3+……+k =.··································································4分43333那么,当n=k+1时,有k2(k1)21+2+3+……+k+(k+1)=+(k+1)3.········································6分422(k1)2(k2)22k2k4k4=(k+1)(+k+1)=(k+1)=444(k1)[(k1)1]2=.··················································································9分433333这就是说,当n=k+1时,等式也成立.···························································10分根据(1)和(2),可知对n∈N某等式成立.·······················································12分18.解:设摸出红球的个数为某,则某服从超几何分布,其中N=30,M=10,n=5.············································································4分于是中奖的概率为P(某≥3)=P(某=3)+P(某=4)+P(某=5) (6)分353454555C10C30C10C30C10C30101010=++································································9分555C30C30C30≈0.191.······································································································12分19.解:根据月工资的分布列,可得E某1=1200某0.4+1400某0.3+1600某0.2+1800某0.1=1400.··································································································2分22D某1=(1200-1400)某0.4+(1400-1400)某0.3+(1600-1400)2某0.2+(1800-1400)2某0.1=40000···································································································4分E某2=1000某0.4+1400某0.3+1800某0.2+2200某0.1=1400·····································································································6分D某2=(1000-1400)2某0.4+(1400-1400)2某0.3篇二:2022高二数学下册寒假作业答案D.4某-3y+7=08.过点的直线中,被截得最长弦所在的直线方程为()A.B.C.D.9.(2022年四川高考)圆的圆心坐标是10.圆和的公共弦所在直线方程为____.11.(2022年天津高考)已知圆的圆心是直线与轴的交点,且圆与直线相切,则圆的方程为.12(2022山东高考)已知圆过点,且圆心在轴的正半轴上,直线被该圆所截得的弦长为,则圆的标准方程为____________13.求过点P(6,-4)且被圆截得长为的弦所在的直线方程.14、已知圆C的方程为某2+y2=4.(1)直线l过点P(1,2),且与圆C交于A、B两点,若|AB|=23,求直线l的方程;(2)圆C上一动点M(某0,y0),ON=(0,y0),若向量OQ=OM+ON,求动点Q的轨迹方程人的结构就是相互支撑,众人的事业需要每个人的参与。
2023高二历史寒假作业及答案

2023高二历史寒假作业及答案(实用版)编制人:__________________审核人:__________________审批人:__________________编制单位:__________________编制时间:____年____月____日序言下载提示:该文档是本店铺精心编制而成的,希望大家下载后,能够帮助大家解决实际问题。
文档下载后可定制修改,请根据实际需要进行调整和使用,谢谢!并且,本店铺为大家提供各种类型的教育资料,如幼儿教案、音乐教案、语文教案、知识梳理、英语教案、物理教案、化学教案、政治教案、历史教案、其他范文等等,想了解不同资料格式和写法,敬请关注!Download tips: This document is carefully compiled by this editor.I hope that after you download it, it can help you solve practical problems. The document can be customized and modified after downloading, please adjust and use it according to actual needs, thank you!Moreover, this store provides various types of educational materials for everyone, such as preschool lesson plans, music lesson plans, Chinese lesson plans, knowledge review, English lesson plans, physics lesson plans, chemistry lesson plans, political lesson plans, history lesson plans, and other sample texts. If you want to learn about different data formats and writing methods, please stay tuned!2023高二历史寒假作业及答案本店铺就给大家整理了2023高二历史寒假作业答案,供家长参考。
对口单招一点通高二寒假作业答案

对口单招一点通高二寒假作业答案示例文章篇一:《对口单招一点通高二寒假作业答案》一、语文部分(一)古诗词鉴赏题目:赏析李白《蜀道难》中“蜀道之难,难于上青天”这句诗的表达效果。
答案:“蜀道之难,难于上青天”这一句在全诗中有着极为关键的作用。
从字面来看,它直接说出了蜀道的艰难程度比登上青天还要难。
这是一种夸张的手法,就像说一个人的力气大得能拔起一座山一样。
通过这种夸张,诗人将蜀道的艰险直观地展现在读者眼前。
它奠定了全诗的情感基调,那就是对蜀道艰险的惊叹与敬畏。
这就好比我们看到一座高耸入云的山峰,第一反应就是“哇,这山好高,高得仿佛能戳破天空”。
它在诗中的反复出现,像一根线一样贯穿全诗,每次出现都加深了读者对蜀道难的印象。
这一句不仅是在说道路的难行,更像是在诉说人生道路上那些难以跨越的坎坷,让人感叹不已。
(二)文言文阅读题目:《劝学》中有“积土成山,风雨兴焉;积水成渊,蛟龙生焉;积善成德,而神明自得,圣心备焉。
故不积跬步,无以至千里;不积小流,无以成江海。
”请阐述其蕴含的哲理。
答案:这里面蕴含着深刻的哲理呢。
就像我们盖房子,一块砖一块砖地垒起来,最后才能成为一座坚固的房子。
积土多了能成山,山高大了就会引起风雨,这是一种自然的积累产生质变的现象。
积水成渊也是一样的道理,小小的水洼汇聚成渊,就有蛟龙产生了。
在品德修养上,不断积累善事就能成为有德之人,那时候就如同神明附身一样,圣心也就具备了。
而后面说不积跬步就到不了千里之外,不汇聚小流就成不了江海。
这告诉我们做任何事都要从点滴做起啊。
如果一个人想要成功,却不愿意一步一步脚踏实地,那怎么可能到达远方呢?这就像一个人想要收获满仓的粮食,却不愿意去播种一粒种子,这不是很荒谬吗?这就提醒我们,无论是学习还是做人,都要有耐心,不断积累,才能达到目标。
(三)现代文阅读题目:在一篇描写故乡的散文中,作者多次提到故乡的老槐树,这有什么作用?答案:作者多次提到故乡的老槐树呀,那作用可多啦。
高二年级物理寒假作业答案5、6

高二年级寒假作业(物理必修)作业5答案
1、A
2、B
3、C
4、C
5、D
6、B
7、C
8、B
9、C 10、D 11、D 12、A 13、B
14、高于 5
15、(1)第一次上滑过程中物体的加速度大小a : 根据匀变速直线运动
(2)第二次上滑过程中物体可能的运动情况是:
①先做匀加速上滑,撤去推力后匀减速上滑;
②先匀速上滑,撤去推力后匀减速上滑;
③先做加速度较小的匀减速运动,撤去推力后再做加速度较大的匀减速。
(3)第二次上滑过程中推力对物体做的功W :
根据动能定理有:
高二年级寒假作业(物理必修)作业6答案
1、D
2、A
3、B
4、A
5、A
6、B
7、D
8、D
9、B 10、D
11、(1)⑤⑥⑦ 重锤、低压交流电源、刻度尺 (2)D (3)7.62m 7.59m 略小于 空气阻力和摩擦阻力
12、(1)gl 2 (2)3mg
13、(1)303m (2)15m (3)o 30=θ。
高二营销专业《基础会计》寒假作业五
新高三营销专业暑假作业基础会计(五) 姓名:(总分:150分;时间:75分钟)一、单项选择题(每题1分共30分)1.不需要进行会计核算的经济业务事项是()。
A、从银行提取现金B、签订销售合同C、收取销售订金D、结算销售货款2.根据会计法规定,有权制定国家统一的会计制度的部门是()。
A、国家发改委B、国资委C、财政部D、审计署3.会计的本质是()。
A、反映与分析B、核算与监督C、一种管理活动D、记账、算账、报账4.材料采购人员外出采购原材料的差旅费,应该记入材料采购成本,但因其金额小,在会计实务中作为管理费用处理,这是依据会计核算的()。
A、及时性原则B、明晰性原则C、谨慎性原则D、重要性原则5.某企业今年10月份支付四季度报刊杂志费1200元,支付本月工资20000元,支付购A材料款9000元,发生水电费用1600元,款项尚未支付。
按权责发生制原则,该企业10月份的费用为()。
A、31800B、30200C、22800D、220006.某单位7月份仅生产A产品1200件,且全部完工入库,每件成本100元,本月售出A产品1000件,每件售价140元,此外发生相关费用10000元,按配比性原则,该单位7月份的利润()。
A、 20000B、40000C、30000D、500007.如果企业将一项资本性支出作为收益性支出核算,将使本期的()。
A、成本费用增加B、成本费用减少C、成本费用不变D、净收益增加8.企业计提固定资产折旧是以( )假设为前提的。
A、会计主体B、货币计量C、持续经营D、历史成本9.属于流动负债的项目是()。
A、长期借款B、预付账款C、预收账款D、其他应收款10.下列项目中,符合资产定义的是( )。
A、购入的某项专利权B、经营租入的设备C、待处理的财产损失D、计划购买的某项设备11.下列符合费用定义的是()。
A、销售商品时结转的已销售商品的成本B、存库商品因自然灾害发生的损失C、发生的投资损失D、罚款支出12.关于利润,下列说法中错误的是( )。
高二物理必修寒假作业参考答案
高二物理(必修)寒假作业(一)参考答案一、单项选择题:每小题只有一个选项符合题意(二25小题6分,共10分).24-1.D;25.(1)D(2)(a)0.490.48(b)在误差允许的范围内,机械能守恒。
三、计算题(本大题3小题,其中26小题6分,27小题7分,28小题8分,共21分)26.(1)300N(2)0.5S(3)0.125m27.(1)2m/s2(2)22m/s(3)-4J2(2)(3/2)R(3)28.(1)RR=H/2D O最大距离为H高二物理(必修)寒假作业(二)参考答案一二、填空题24.B L2B L v25.交流小于重力加速度g三、解答题26.(1)a=2.5m/s2(2)v=5m/s(3)t2=4s 27.(1)E k=3.6×104J(2)P=2.88×103J(3)W f =5.4×105J28.(1)gl v m m A B 2= (2)gH v v 22+=' (3)2222l L g H v s +⎪⎪⎭⎫ ⎝⎛+=高二物理(必修)寒假作业(三)参考答案2425. 0.497 0.15526.(7分)(1)2×104N (2)22.5m (3)3×105W 27.(7分)解:(1)汽车受重力G 和拱桥的支持力F ,二力平衡,故F =G =5000N (1分)根据牛顿第三定律,汽车对拱桥的压力为5000N (1分)(2)汽车受重力G 和拱桥的支持力F,根据牛顿第二定律有G -F =r v m 2故rv m G F 2-==4000N根据牛顿第三定律,汽车对拱桥的压力为4000N (3分)(3)汽车只受重力GG =rv m 2gr v ==510m /s(2分)28.( 9 分)解:由机械能守恒定律可得:mgH mV =2021,所以货物在B 点的速度为V 0=10m /s (1)货物从B 到C 做匀减速运动,加速度2/6s m g m mg a ===μμ设到达C 点速度为V C ,则:aL V V C 2220=-,所以:V C =2 m /s落地点到C 点的水平距离:m 6.02=⋅=ghV S C (2分)(2)皮带速度 V 皮=ω·R =4 m /s , 同(1)的论证可知:货物先减速后匀速,从C 点抛出的速度为V C =4 m /s , 落地点到C点的水平距离:m 2.12=⋅=gh V S C(1分)(3)①皮带轮逆时针方向转动: 无论角速度为多大,货物从B 到C 均做匀减速运动:在C 点的速度为V C =2m /s ,落地点到C 点的水平距离S =0.6m (1分) ②皮带轮顺时针方向转动时:Ⅰ、0≤ω≤10 r a d /s 时, S =0.6m (1分)Ⅱ、10<ω<50 r a d /s时,S =ω·Rgh 2=0.06ω(1分)Ⅲ、50<ω<70 r a d /s时,S =ω·Rgh 2=0.06ω (1分)Ⅳ、ω≥70 r a d /s时,S =ghv c 2⋅=4.2m (1分) S —ω图象如图 (1分)高二物理(必修)寒假作业(四)参考答案一.选择题0二.填空题24. 0.86 41526329S S S S S S a T-+-+-=0.6425.三.计算题 26.(1)a =8m /s 2(2)10N27.(1)21()2kA E mv mg H h =-- (2)212W mv mgH =- 28.(1)10 m /s(2)0.875N(3)FN=8F -1(F ≥0.25N ) 图略高二物理(必修)寒假作业(五)参考答案一二24. A25. 0.1 , 3.6 ,1.2 , 0.42三,解答题(每小题7分,共21分)26.(1)1.8m /s 2 (2)18m /s (3)108N 27. (1)20J (2)20m /s(1)6m /s (2) 4.5m高二物理(必修)寒假作业(六)参考答案一、单项选择题:每小题只有一个....选项符合题意(本部分23小题,每小题3分,共69分) 1:)12(:)23(1:2:3--二.填空题:把答题填在答题卡相应的横线上(本部分2小题,其中24小题4分,25小题6分,共10分)24-A .(4分)25 5(每空2分) 24-B .(4分) 5 2(每空2分)25.(6分0.1 0.78 3.2 (每空2分)三、计算或论述题:解答时请写出必要的文字说明、方程式和重要的演算步骤,只写出最后答案的不能得分,有数值计算的题,答案中必须明确写出数值和单位(本部分3小题,其中26小题6分,27小题7分,28小题8分,共21分)26.(6分)解答:(1)物体在水平拉力作用过程中2111112m/s v v a t t ∆-===∆ (1分) 0.5kg Fm a==(1分) (2)物体在竖直拉力作用过程中2F mg ma -=(1分)222m/s F mga m-==(1分)(3)由速度-位移关系2222v a x =变形得:2224m 2v x a ==(2分)27.(7分) 解答:(1)运动员从a 点滑行至C 点的过程中满足机械能守恒定律212mgh mv = (1分)s m v /24= (1分)(2)根据平抛运动的相应规律可得vt x = 221gt y =(1分) 而有几何关系可知θtan x y = (1分)由此解得:运动员从C点运动到着地点b 的时间为s t 6.3= (1分)(3)运动员从a点滑行至C点过程中,由动能定理得212f mgh W mv '-=克 (1分)2760f W =克(1分)28.(8分)解答:(1)由题设条件可判断:此时弹簧伸长量为x =2c m ,相应的弹力大小为N kx F 1.0== (1分)于是由平衡条件可知:小物体A 所受到的静摩擦力大小为N F f 1.0== (1分) (2)分析可知:随角速度逐渐增大,A 物体所受到的摩擦力率先减为零,此时的角速度可由2111ωr m F = (2分)求得为s rad /2101=ω (1分) (3)假设角速度增大为ω1时A 物体将率先滑动,则应有 21111ωμr m F g m =+ (1分)假设角速度增大为ω2时B 物体将率先滑动,则又应有 22222ωμr m F g m =- (1分)于是,所求的ω应在ω1和ω2中取其较小者,即s rad /110211==ωω (1分)高二物理(必修)寒假作业(七)参考答案一、单项选择题:每小题只有一个选项符合题意(二、填空题:把答案填在答题卡相应的横线上(本部分2小题,其中24小题4分,25小题6分,共10分)。
高二语文寒假作业答案四
高二年级寒假作业八(语文)一、现代文阅读一(20分)1.(4分)对儿女们来说,外出打工是一条路途遥远充满艰辛的谋生之路;对在家的老人们来说,儿女外出就意味着那就是一条追随儿女身影的绵长的牵挂思念之路。
(评分标准:写出“遥远而艰辛的谋生之路”、“绵长的牵挂”相近的意思,各得2分。
)2.(4分)运用想象(或联想)的手法(2分)。
丰富文章内容(1分);突出“中国地图”的作用,形象生动地表述“我的亲戚们”对外地务工儿女的牵挂(1分)。
[想象(或联想)的手法如答成“心理描写”不得分。
]3.(6分)(从内容看)新民谣把当地人外出打工现象由上文的“我”的亲人扩大到整个地区,进一步说明该现象的普遍,丰富了内容,深化了主旨(2分);(从结构上看)点明题目,呼应开头,使文章结构完整,使“中国地图”这一核心意象得以突出(2分);(从表达看)民谣语言生动活泼,朗朗上口,富于地方特色,使文章表达有变化,颇具乡土情趣(2分)。
[评分标准:答出“说明该现象普遍”、“点题”(或“呼应开头”或“突出中国地图核心意象”)、“表达生动活泼”中一点,得2分。
]4.(6分)①反映家乡现实状况,表达对故乡亲人辛酸生活的关注和同情;②对“为生活而外出务工”社会普遍现象的思考,对外出务工的合理性进行反思;③希望读者能深入理解外出务工人员的辛苦进而能同情、善待他们。
④抒发留守老人对在外打工的子女的牵挂之情(评分标准:答出一点得2分,如有其他答案,有道理的,斟情给分。
)二、现代文阅读二(20分)5.被收留的冉阿让偷了教堂里的银器,卞福汝主教认为银器本属于穷人不必追究,并在警察面前为冉阿让开脱,努力用自己的言行感化冉阿让。
(这四个主要情节必须有,一个1分,少一个扣1分,如语句不简明适当扣分)6.对比衬托(1分)。
马格洛大娘的愤愤不平(1分)、警察对冉阿让的恶狠狠(1分)、冉阿让震惊和失语(1分)都衬托出了卞福汝主教的仁慈宽容(2分)。
7.冉阿让刚从被指认为小偷的高度紧张中松弛下来(2分),惊喜(悲喜)、愧疚(羞愧)、后悔,百感交集(2分)。
高二数学寒假作业(含答案)
数学寒假作业(一)测试范围:解三角形使用日期:腊月十九 测试时间:120分钟一、选择题(本大题共12个小题,每个小题5分,共60分,每小题给出的四个备选答案中,有且仅有一个是符合题目要求的)1.△ABC 的内角A 、B 、C 的对边分别为a 、b 、c ,若c =2,b =6,B =120°,则a 等于( )A. 6 B .2 C. 3 D. 22.在△ABC 中,若AB =3-1,BC =3+1,AC =6,则B 等于( ) A .30° B .45° C .60° D .120°3.在△ABC 中,A =45°,AC =4,AB =2,那么cos B =( ) A.31010 B .-31010 C.55D .-554.等腰△ABC 底角B 的正弦与余弦的和为62,则它的顶角是( ) A .30°或150° B .15°或75° C .30° D .15°5.从A 处望B 处的仰角为α,从B 处望A 处的俯角为β,则α、β的关系为( ) A .α>β B .α=β C .α+β=90°D .α+β=180°6.(2012·天津理,6)在△ABC 中,内角A 、B 、C 所对的边分别是a 、b 、c ,已知8b =5c ,C =2B ,则cos C =( )A.725 B .-725 C .±725D.24257.△ABC 的三边分别为2m +3,m 2+2m ,m 2+3m +3(m >0),则最大内角度数为( ) A .150° B .120° C .90°D .135°8.在△ABC 中,若sin A >sin B ,则A 与B 的大小关系为( ) A .A >B B .A <B C .A ≥B D .A ,B 的大小关系不能确定9.△ABC 的三个内角A 、B 、C 所对的边分别为a 、b 、c ,若a sin A sin B +b cos 2A =2a ,则ba =( )A .2 3B .2 2 C. 3D. 210.在△ABC 中,a 2+b 2-ab =c 2=23S △ABC ,则△ABC 一定是( ) A .等腰三角形 B .直角三角形 C .等边三角形 D .等腰直角三角形11.在△ABC 中,若|AB →|=2,|AC →|=5,AB →·AC →=-5,则S △ABC =( )A.532B. 3C.52 D .512.如果△A 1B 1C 1的三个内角的余弦值分别等于△A 2B 2C 2的三个内角的正弦值,则( ) A .△A 1B 1C 1和△A 2B 2C 2都是锐角三角形 B .△A 1B 1C 1和△A 2B 2C 2都是钝角三角形C .△A 1B 1C 1是钝角三角形,△A 2B 2C 2是锐角三角形D .△A 1B 1C 1是锐角三角形,△A 2B 2C 2是钝角三角形二、填空题(本大题共4个小题,每个小题4分,共16分.将正确答案填在题中横线上) 13.三角形一边长为14,它对的角为60°,另两边之比为85,则此三角形面积为________.14.在△ABC 中,若tan A =13,C =150°,BC =1,则AB =________.15.如图,已知梯形ABCD 中,CD =2,AC =19,∠BAD =60°,则梯形的高为__________.16.在△ABC 中,cos 2A 2=b +c2c ,则△ABC 的形状为________.三、解答题(本大题共6个小题,共74分,解答应写出文字说明,证明过程或演算步骤) 17.(本题满分12分)在△ABC 中,a ,b ,c 分别是角A 、B 、C 的对边,若tan A =3,cos C =55.(1)求角B 的大小;(2)若c =4,求△ABC 面积.18.(本题满分12分)在△ABC 中,已知a =6,A =60°,b -c =3-1,求b 、c 和B 、C .19.(本题满分12分)如图,某海轮以30n mile/h 的速度航行,在点A 测得海面上油井P 在南偏东60°,向北航行40min 后到达点B ,测得油井P 在南偏东30°,海轮改为北偏东60°的航向再航行80min 到达C 点,求P 、C 间的距离.20.(本题满分12分)在△ABC 中,a 、b 、c 分别为内角A 、B 、C 的对边,且2a sin A =(2b +c )sin B +(2c +b )sin C . (1)求A 的大小;(2)若sin B +sin C =1,试判断△ABC 的形状.21.(本题满分12分)在△ABC 中,角A 、B 、C 所对的边分别为a 、b 、c ,已知cos2C =-14.(1)求sin C 的值;(2)当a =2,2sin A =sin C ,求b 及c 的长.22.(本题满分14分)在△ABC中,角A、B、C的对边分别为a、b、c,已知3cos(B-C)-1=6cos B cos C.(1)求cos A的值;(2)若a=3,△ABC的面积为2,求b、c.家长签字:日期:数学寒假作业(一)答案1、[答案] D2、[答案] C[解析] cos B =AB 2+BC 2-AC 22AB ·BC =12,∴B =60°.3、[答案] D4、[答案] A5、[答案] B[解析] 仰角和俯角都是水平线与视线的夹角,故α=β.6、[答案] A7、[答案] B8、解析:由正弦定理a sin A =bsin B ,∴a >b .∴A >B .答案:A 9、[答案] D[解析] ∵a sin A sin B +b cos 2A =2a ,∴由正弦定理,得sin 2A sin B +sin B cos 2A =2sin A ,∴sin B (sin 2A +cos 2A )=2sin A ,∴sinB =2sin A ,∴sin B sin A = 2.由正弦定理,得ba =sin Bsin A = 2.10、[答案] B[解析] 由a 2+b 2-ab =c 2得:cos C =a 2+b 2-c 22ab =12,∴∠C =60°,又23S △ABC =a 2+b 2-ab ,∴23×12ab ·sin60°=a 2+b 2-ab ,得2a 2+2b 2-5ab =0,即a =2b 或b =2a . 当a =2b 时,代入a 2+b 2-ab =c 2得a 2=b 2+c 2;当b =2a 时,代入a 2+b 2-ab =c 2得b 2=a 2+c 2.故△ABC 为直角三角形.11、[答案] A[解析] AB →·AC →=|AB →|·|AC →|cos A =10cos A =-5,∴cos A =-12,∴sin A =32,∴S △ABC =12|AB →|·|AC →|·sin A =532.12、[答案] D[解析] 由条件知,△A 1B 1C 1的三个内角的余弦值均大于0,则△A 1B 1C 1是锐角三角形,假设△A 2B 2C 2是锐角三角形,由⎩⎪⎨⎪⎧ sin A 2=cos A 1=sin π2-A 1sin B 2=cos B 1=sin π2-B 1sin C 2=cos C 1=sinπ2-C 1,得⎩⎪⎨⎪⎧A 2=π2-A 1B 2=π2-B1C 2=π2-C1,那么,A 2+B 2+C 2=π2,这与三角形内角和为180°相矛盾,故假设不成立, 即△A 2B 2C 2是钝角三角形,故选D.13、[答案] 403[解析] 设另两边长为8x 和5x ,则cos60°=64x 2+25x 2-14280x 2得x =2,另两边长为16和10,此三角形面积为S =12×16×10·sin60°=40 3. 14、[答案]102[解析] ∵tan A =13,∴sin A =1010,由正弦定理,得AB =BC ·sin C sin A =102. 15、[答案] 332[解析] 解法一:∵∠BAD =60°,∴∠ADC =180°-∠BAD =120°.∵CD =2,AC =19,∴19sin120°=2sin ∠CAD ,∴sin ∠CAD =5719. ∴sin ∠ACD =sin(60°-∠CAD )=35738.∴AD =AC ·sin ∠ACD sin D=19×35738sin120°=3.∴h =AD ·sin60°=332. 解法二:在△ACD 中,AC 2=AD 2+CD 2-2AD ·CD cos120°,∴AD 2+2AD -15=0.∴AD =3 (AD =-5舍去).∴h =AD sin60°=332.16、[答案] 直角三角形[解析] ∵cos 2A 2=1+cos A 2=b +c 2c =12+b2c ,∴cos A =b c .由余弦定理,得cos A =b 2+c 2-a 22bc ,∴b 2+c 2-a 22bc =bc ,∴a 2+b 2=c 2.∴△ABC 为直角三角形.17、[解析] (1)∵cos C =55,∴sin C =255,∴tan C =2.∵tan B =-tan(A +C )=-tan A +tan C 1-tan A tan C =-3+21-3×2=1,又0<B <π,∴B =π4.(2)由正弦定理,得b sin B =c sin C ,∴b =c ×sin B sin C =4×22255=10.∵B =π4,∴A =3π4-C .∴sin A =sin(3π4-C )=sin 3π4cos C -cos 3π4sin C =22×55-(-22)×255=31010.∴S △ABC =12bc sin A =12×10×4×31010=6.18、[解析] 由余弦定理,得6=b 2+c 2-2bc cos60°,∴b 2+c 2-bc =6 ①由b -c =3-1平方得:b 2+c 2-2bc =4-2 3 ② ①、②两式相减得bc =2+2 3.由⎩⎨⎧b -c =3-1bc =2+23,解得⎩⎨⎧b =3+1c =2,由正弦定理,得sin B =b sin Aa =3+1sin60°6=6+24.∵6<3+1,∴B =75°或105°.∵a 2+c 2>b 2,∴B 为锐角, ∴B =75°,从而可知C =45°.[点评] 求角B 时,若先求得sin C =c sin A a =22,∵a >c ,∴C =45°,从而得B =75°. 若用余弦定理cos B =a 2+c 2-b 22ac =6-24,∴B =75°. 19、[解析] AB =30×4060=20,BC =30×8060=40.在△ABP 中,∠A =120°,∠ABP =30°,∠APB =30°, ∴BP =ABsin ∠APB ·sin ∠BAP =20sin30°sin120°=20 3. 在Rt △BCP 中,PC =BC 2+BP 2=402+2032=207.∴P 、C 间的距离为207nmile.20、[解析] (1)由已知,根据正弦定理,得2a 2=(2b +c )b +(2c +b )c ,即a 2=b 2+c 2+bc .由余弦定理,得a 2=b 2+c 2-2bc cos A ,故cos A =-12,A =120°.(2)由a 2=b 2+c 2+bc ,得sin 2A =sin 2B +sin 2C +sin B sin C .又sin B +sin C =1,故sin B =sin C =12.因为0°<B <90°,0°<C <90°,故B =C . 所以△ABC 是等腰的钝角三角形.21、[解析] (1)∵cos2C =1-2sin 2C =-14,0<C <π,∴sin C =104.(2)当a =2,2sin A =sin C 时,由正弦定理a sin A =csin C ,得c =4. 由cos2C =2cos 2C -1=-14及0<C <π,得cos C =±64.由余弦定理,得c 2=a 2+b 2-2ab cos C ,得b 2±6b -12=0(b >0),解得b =6或26,∴⎩⎨⎧b =6c =4,或⎩⎨⎧b =26c =4.22、[解析] (1)由3cos(B -C )-1=6cos B cos C ,得3(cos B cos C -sin B sin C )=-1,即cos(B +C )=-13,∴cos A =-cos(B +C )=13.(2)∵0<A <π,cos A =13,∴sin A =223.由S △ABC =22,得12bc sin A =22, ∴bc =6.由余弦定理,得a 2=b 2+c 2-2bc cos A ,∴9=(b +c )2-2bc (1+cos A )=(b +c )2-16, ∴b +c =5. 由⎩⎪⎨⎪⎧ b +c =5bc =6,得⎩⎪⎨⎪⎧ b =2c =3或⎩⎪⎨⎪⎧b =3c =2.数学寒假作业(二)测试范围:数列使用日期:腊月二十一 测试时间:120分钟一、选择题(本大题共12小题,每小题5分,共60分.在每小题给出的四个选项中,只有一项是符合题目要求的)1.已知a n =cos n π,则数列{a n }是( )A .递增数列B .递减数列C .常数列D .摆动数列 2.在数列2,9,23,44,72,…中,第6项是( ) A .82 B .107 C .100 D .833.等差数列{a n }的前n 项和为S n ,若S 2=2,S 4=10,则S 6等于( ) A .12 B .18 C .24 D .424.数列{a n }中,a 1=1,对所有n ≥2,都有a 1a 2a 3…a n =n 2,则a 3+a 5=( ) A.6116 B.259 C.2516 D.31155.已知{a n }为等差数列,a 2+a 8=12,则a 5等于( ) A .4 B .5 C .6 D .76.在数列{a n }中,a 1=2,a n +1=a n +ln(1+1n),则a n =( )A .2+ln nB .2+(n -1)ln nC .2+n ln nD .1+n +ln n7.已知{a n }为等差数列,a 1+a 3+a 5=105,a 2+a 4+a 6=99.以S n 表示{a n }的前n 项和,则使得S n 达到最大值的n 是( )A .21B .20C .19D .188.设等差数列{a n }的前n 项和为S n .若a 1=-11,a 4+a 6=-6,则当S n 取最小值时,n 等于( )A .6B .7C .8D .99.等比数列{a n }的前n 项和为S n ,且4a 1,2a 2,a 3成等差数列.若a 1=1,则S 4等于( ) A .7 B .8 C .15 D .1610.如果数列{a n }满足a 1,a 2-a 1,a 3-a 2,…,a n -a n -1,…是首项为1,公比为2的等比数列,那么a n =( )A .2n +1-1 B .2n -1 C .2n -1D .2n+111.含2n +1个项的等差数列,其奇数项的和与偶数项的和之比为( ) A.2n +1n B.n +1n C.n -1n D.n +12n12.如果数列{a n }满足a 1=2,a 2=1,且a n ·a n -1a n -1-a n =a n ·a n +1a n -a n +1,那么此数列的第10项为( )A.1210 B.129 C.110 D.15二、填空题(本大题共4个小题,每小题5分,共20分,把答案填在题中的横线上) 13.等比数列{a n }中,a 3=12, a 5=48,那么a 7=________.14.已知数列{a n }的前n 项和为S n =n 2+1,则数列{a n }的通项公式为a n =________. 15.已知等差数列{a n },{b n }的前n 项和分别为A n ,B n ,且满足A n B n =2n n +3,则a 1+a 2+a 12b 2+b 4+b 9=________.16.在数列{a n }中,a 1=1,(n +1)a n =(n -1)a n -1(n ≥2),S n 是其前n 项的和,则S n 等于________.三、解答题(本大题共6个小题,共70分,解答应写出文字说明、证明过程或演算步骤) 17.(10分)公差d ≠0的等差数列{a n }的前n 项和为S n ,若a 4是a 3与a 7的等比中项,且S 8=32,求S 10的大小.18.(12分)等差数列{a n}中,a4=10,且a3,a6,a10成等比数列,求数列{a n}前20项的和S20.19.(12分)已知数列{a n}的首项a1=3,通项a n=2n p+nq(n∈N*,p,q为常数),且a1,a4,a5成等差数列,求:(1)p,q的值;(2)数列{a n}的前n项和S n的公式.20.(12分)设{a n}为等比数列,{b n}为等差数列,且b1=0,c n=a n+b n,若{c n}是1,1,2,…,求数列{c n}的前10项的和.21.(12分)已知数列{a n }满足a 1=1,a 2=2,a n +2=a n +a n +12,n ∈N *.(1)令b n =a n +1-a n ,证明:{b n }是等比数列;(2)求{a n }的通项公式.22.(12分)设数列{a n }满足a 1+3a 2+32a 3+…+3n -1a n =n3,a ∈N *.(1)求数列{a n }的通项;(2)设b n =n a n,求数列{b n }的前n 项和S n .家长签字:日期:数学寒假作业(二)答案1、答案 D2、答案 B3、答案 C解析 思路一:设公差为d ,由题意得⎩⎪⎨⎪⎧2a 1+d =2,4a 1+6d =10,解得a 1=14,d =32.则S 6=6a 1+15d =24.思路二:S 2,S 4-S 2,S 6-S 4也成等差数列,则2(S 4-S 2)=S 6-S 4+S 2,所以S 6=3S 4-3S 2=24.4、答案 A5、答案 C解析 由等差数列的性质可知a 2、a 5、a 8也成等差数列,故a 5= a 2+a 82=6,故选C.6、答案 A解析 依题意得a n +1-a n =lnn +1n ,则有a 2-a 1=ln 21,a 3-a 2=ln 32,a 4-a 3=ln 43,…,a n -a n -1=ln n n -1,叠加得a n -a 1=ln(21·32·43·…·nn -1)=ln n ,故a n =2+ln n ,选A.7、答案 B解析 ∵a 1+a 3+a 5=105,a 2+a 4+a 6=99, ∴3a 3=105,3a 4=99,即a 3=35,a 4=33. ∴a 1=39,d =-2,得a n =41-2n .令a n =0且a n +1<0,n ∈N *,则有n =20.故选B. 8、答案 A解析 设等差数列{a n }的公差为d ,∵a 4+a 6=-6,∴a 5=-3,∴d =a 5-a 15-1=2,∴a 6=-1<0,a 7=1>0,故当等差数列{a n }的前n 项和S n 取得最小值时,n 等于6.9、答案 C解析 由4a 1+a 3=4a 2⇒4+q 2=4q ⇒q =2,则S 4=a 1+a 2+a 3+a 4=1+2+4+8=15.故选C.10、答案 B 11、答案 B 12、答案 D 解析 ∵a n ·a n -1a n -1-a n =a n ·a n +1a n -a n +1,∴{a n ·a n -1a n -1-a n }为常数列.∴a n ·a n -1a n -1-a n =a 2·a 1a 1-a 2=2,∴a n ·a n -1=2a n -1-2a n .∴1a n -1a n -1=12,∴{1a n }为等差数列,1a 1=12,d =12.∴1a n =12+(n -1)·12=n 2.∴a n =2n,∴a 10=15.13、解析:由题意可知a 3,a 5,a 7成等比数列,∴a 25=a 3·a 7,∴a 7=48212=192.14、解析:当n ≥2时,a n =S n -S n -1=n 2-(n -1)2=2n -1. 又当n =1时,a 1=S 1=2不满足a n =2n -1,∴a n =⎩⎪⎨⎪⎧2 n =1,2n -1n ≥2.15、解析:a 1+a 2+a 12b 2+b 4+b 9=3a 1+12d 13b 1+12d 2=a 5b 5=a 1+a 92b 1+b 92=9×a 1+a 929×b 1+b 92=A 9B 9=2×99+3=32. 16、解析:∵(n +1)a n =(n -1)a n -1, ∴a n a n -1=n -1n +1,∴a n =a n a n -1·a n -1a n -2·…·a 3a 2·a 2a 1·a 1=n -1n +1·n -2n ·n -3n -1·…·24·13·1=2n n +1=2(1n -1n +1).∴S n =2(1-1n +1)=2n n +1.17、解:根据题意得⎩⎪⎨⎪⎧a 1+3d 2=a 1+2d a 1+6d ,8a 1+28d =32,解得⎩⎪⎨⎪⎧a 1=-3,d =2.所以S 10=S 8+a 9+a 10=32+2a 1+17d =60.18、解析 设数列{a n }的公差为d ,则a 3=a 4-d =10-d ,a 6=a 4+2d =10+2d .a 10=a 4+6d =10+6d .由a 3,a 6,a 10成等比数列,得a 3a 10=a 26. 即(10-d )(10+6d )=(10+2d )2, 整理得10d 2-10d =0,解得d =0或d =1. 当d =0时,S 20=20a 4=200;当d =1时,a 1=a 4-3d =10-3×1=7. 于是S 20=20a 1+20×192d =20×7+190=330.19、解:(1)由a 1=3,得2p +q =3,又a 4=24p +4q ,a 5=25p +5q ,且a 1+a 5=2a 4,得3+25p +5q =25p +8q ,解得p =1,q =1. (2)由(1)得a n =2n+n ,S n =(2+22+…+2n )+(1+2+…+n )=2n +1-2+n n +12.20、解析 ∵c 1=a 1+b 1,即1=a 1+0,∴a 1=1.又⎩⎪⎨⎪⎧a 2+b 2=c 2,a 3+b 3=c 3,即⎩⎪⎨⎪⎧q +d =1, ①q 2+2d =2. ②②-2×①,得q 2-2q =0. 又∵q ≠0,∴q =2,d =-1.c 1+c 2+c 3+…+c 10=(a 1+a 2+a 3+…+a 10)+(b 1+b 2+b 3+…+b 10) =a 11-q 101-q +10b 1+10×92d =210-1+45·(-1)=978.21.(12分)已知数列{a n }满足a 1=1,a 2=2,a n +2=a n +a n +12,n ∈N *.(1)令b n =a n +1-a n ,证明:{b n }是等比数列; (2)求{a n }的通项公式.21、解析 (1)b 1=a 2-a 1=1,当n ≥2时,b n =a n +1-a n =a n -1+a n2-a n =-12(a n -a n -1)=-12b n -1, ∴{b n }是以1为首项,-12为公比的等比数列.(2)由(1)知b n =a n +1-a n =(-12)n -1,当n ≥2时,a n =a 1+(a 2-a 1)+(a 3-a 2)+…+(a n -a n -1) =1+1+(-12)+…+(-12)n -2=1+1--12n -11--12=1+23=53-23(-12)n -1,当n =1时,53-23(-12)1-1=1=a 1.∴a n =53-23(-12)n -1(n ∈N *).22、解:(1)a 1+3a 2+32a 3+…+3n -1a n =n3,a 1+3a 2+32a 3+…+3n -2a n -1=n -13(n ≥2),3n -1a n =n 3-n -13=13(n ≥2),a n =13n (n ≥2).验证n =1时也满足上式,∴a n =13n (n ∈N *).(2)b n =n ·3n,S n =1·3+2·32+3·33+…+n ·3n3S n =1·32+2·33+…+(n -1)·3n +n ·3n +1上述两式相减得: -2S n =3+32+33+3n -n ·3n +1=3-3n +11-3-n ·3n +1.即S n =n2·3n +1-14·3n +1+34.数学寒假作业(三)测试范围:不等式使用日期:腊月二十三 测试时间:100分钟 一、选择题(共10小题,每小题5分,共50分) 1.不等式(x +3)2<1的解集是( )A .{x |x >-2}B .{x |x <-4}C .{x |-4<x <-2}D .{x |-4≤x ≤-2} 2.设M =2a (a -2),N =(a +1)(a -3),则有( ) A .M >N B .M ≥N C .M <N D .M ≤N3.下列命题中正确的是( )A .a >b ⇒ac 2>bc 2B .a >b ⇒a 2>b 2C .a >b ⇒a 3>b 3D .a 2>b 2⇒a >b4.(2012·安徽高考)若x ,y 满足约束条件⎩⎪⎨⎪⎧x ≥0,x +2y ≥3,2x +y ≤3,则z =x -y 的最小值是( )A .-3B .0 C.32 D .35.设x ,y 为正数,则(x +y )⎝ ⎛⎭⎪⎫1x +4y 的最小值为( )A .6B .9C .12D .156.不等式组⎩⎪⎨⎪⎧-2x -3>10,x 2+7x +12≤0的解集为( )A .[-4,-3]B .[-4,-2]C .[-3,-2]D .∅7.已知a ,b ,c 满足c <b <a ,且ac <0,那么下列选项中不一定成立的是( )A .ab >acB .c (b -a )>0C .cb 2<ab 2D .a (a -b )>08. 在如图所示的可行域内(阴影部分且包括边界),目标函数z =x +ay 取得最小值的最优解有无数个,则a 的一个可能值是( )A .-3B .3C .-1D .19. 若直线y =2x 上存在点(x ,y )满足约束条件⎩⎪⎨⎪⎧x +y -3≤0,x -2y -3≤0,x ≥m ,则实数m 的最大值为( )A .-1B .1 C.32D .210.已知x >0,y >0.若2y x +8xy >m 2+2m 恒成立,则实数m 的取值范围是( ) A .m ≥4或m ≤-2 B .m ≥2或m ≤-4 C .-2<m <4 D .-4<m <2 二、填空题(共4小题,每小题5分,共20分) 11.函数y =2-x -4x (x >0)的值域为________. 12.不等式2x 2+2x -4≤12的解集为________.13.已知不等式x 2-ax -b <0的解集为(2,3),则不等式bx 2-ax -1>0的解集为________.14.设D 是不等式组⎩⎪⎨⎪⎧x +2y ≤10,2x +y ≥3,0≤x ≤4,y ≥1,表示的平面区域,则D 中的点P (x ,y )到直线x +y =10的距离的最大值是________.三、解答题(共4小题,共50分) 15.(12分)解下列关于x 的不等式 (1)1<x 2-3x +1<9-x(2)ax2-x-a2x+a<0(a<-1)16.(12分)已知关于x的不等式kx2-2x+6k<0(k≠0).(1)若不等式的解集是{x|x<-3或x>-2},求k的值;(2)若不等式的解集是R,求k的取值范围.17.(12分)一个农民有田2亩,根据他的经验,若种水稻,则每亩每期产量为400千克;若种花生,则每亩每期产量为100千克,但水稻成本较高,每亩每期需240元,而花生只要80元,且花生每千克可卖5元,稻米每千克只卖3元,现在他只能凑足400元,问这位农民对两种作物各种多少亩,才能得到最大利润?18.(14分)已知函数f(x)=x2-2x-8,g(x)=2x2-4x-16,(1)求不等式g(x)<0的解集;(2)若对一切x>2,均有f(x)≥(m+2)x-m-15成立,求实数m的取值范围.家长签字:日期:数学寒假作业(三)答案1.选C 原不等式可化为x 2+6x +8<0,解得-4<x <-2.2.选A 因为M -N =2a 2-4a -(a 2-2a -3)=a 2-2a +3=(a -1)2+2>0,所以M >N . 3.选C 选项A 中,当c =0时,ac 2=bc 2,所以A 不正确;选项B 中,当a =0,b =-1时a >b ,但a 2<b 2,所以B 不正确;选项D 中,当a =-2,b =-1时,a 2>b 2,但a <b ,所以D 不正确.很明显C 正确.4.选A 可行域为如图所示的阴影部分,可知z =x -y 在点A (0,3)处取得最小值,∴z 最小值=-3.5.选B x ,y 为正数,(x +y )·⎝ ⎛⎭⎪⎫1x +4y =1+4+y x +4x y ≥9,当且仅当y =2x等号成立.6.选 A ⎩⎪⎨⎪⎧-2x -3>10x 2+7x +12≤0⇒⎩⎪⎨⎪⎧x -3<-5x +3x +4≤0⇒⎩⎪⎨⎪⎧x <-2-4≤x ≤-3⇒-4≤x ≤-3.7.选C 由已知可得,c <0,a >0,b 不一定,若b =0时,C 不一定成立,故选C. 8.选A 若最优解有无数个,则y =-1a x +z a 与其中一条边平行,而三边的斜率分别为13、-1、0,与-1a 对照可知a =-3或1,又因z =x +ay 取得最小值,则a =-3.9.选B 如图所示:约束条件⎩⎪⎨⎪⎧x +y -3≤0,x -2y -3≤0,x ≥m ,表示的可行域如阴影部分所示.当直线x =m 从如图所示的实线位置运动到过A 点的位置时,m 取最大值.解方程组⎩⎪⎨⎪⎧x +y -3=0,y =2x ,得A 点坐标为(1,2),∴m 的最大值是1,故选B.10.选D ∵x >0,y >0.∴2y x +8x y ≥8(当且仅当2y x =8xy 时取“=”). 若2y x +8xy >m 2+2m 恒成立, 则m 2+2m <8,解之得-4<m <2.11.解析:当x >0时,y =2-⎝ ⎛⎭⎪⎫x +4x ≤2-2x ×4x =-2.当且仅当x =4x ,x =2时取等号.答案:(-∞,-2]12.解析:由已知得2x 2+2x -4≤2-1,所以x 2+2x -4≤-1,即x 2+2x -3≤0,解得-3≤x ≤1.答案:{x |-3≤x ≤1}13.解析:方程x 2-ax -b =0的根为2,3.根据韦达定理得:a =5,b =-6,所以不等式为6x 2+5x +1<0,解得解集为⎝ ⎛⎭⎪⎫-12,-13.答案:⎝ ⎛⎭⎪⎫-12,-1314.解析:画出可行域,由图知最优解为A (1,1),故A 到x +y =10的距离为d =4 2.答案:4 215.解:(1)∵1<x 2-3x +1<9-x , ∴x 2-3x +1>1且x 2-3x +1<9-x . ∴x >3或x <0且-2<x <4. ∴-2<x <0或3<x <4.∴原不等式1<x 2-3x +1<9-x 的解集为{x |-2<x <0或3<x <4}. (2)由ax 2-x -a 2x +a <0 ∴(x -a )(ax -1)<0因a <-1∴(x -a )⎝ ⎛⎭⎪⎫x -1a >0,当a <-1时,1a >a ,所以x <a , 或x >1a .∴不等式的解集为{x |x <a ,或x >1a }.16.解:(1)因为不等式的解集为{x |x <-3或x >-2},所以-3,-2是方程kx 2-2x +6k =0的两根且k <0 .由根与系数的关系得⎩⎪⎨⎪⎧-3×-2=6,-3+-2=2k ,解得k =-25.(2)因为不等式的解集为R ,所以⎩⎪⎨⎪⎧k <0,Δ=4-4k ·6k <0,即⎩⎪⎨⎪⎧k <0,k >66或k <-66.所以k <-66.即k 的取值范围是⎝ ⎛⎭⎪⎫-∞,-66.17.解:设水稻种x 亩,花生种y 亩,则由题意得⎩⎪⎨⎪⎧x +y ≤2,240x +80y ≤400,x ≥0,y ≥0.即⎩⎪⎨⎪⎧x +y ≤2,3x +y ≤5,x ≥0,y ≥0,画出可行域如图阴影部分所示而利润P =(3×400-240)x +(5×100-80)y =960x +420y (目标函数),可联立⎩⎪⎨⎪⎧x +y =2,3x +y =5,得交点B (1.5,0.5).故当x =1.5,y =0.5时,P 最大值=960×1.5+420×0.5=1 650,即水稻种1.5亩,花生种0.5亩时所得到的利润最大. 18.解:(1)g (x )=2x 2-4x -16<0, ∴(2x +4)(x -4)<0,∴-2<x <4, ∴不等式g (x )<0的解集为{x |-2<x <4}. (2)∵f (x )=x 2-2x -8.当x >2时,f (x )≥(m +2)x -m -15恒成立, ∴x 2-2x -8≥(m +2)x -m -15, 即x 2-4x +7≥m (x -1).∴对一切x >2,均有不等式x 2-4x +7x -1≥m 成立. 而x 2-4x +7x -1=(x -1)+4x -1-2≥2x -1×4x -1-2=2(当且仅当x =3时等号成立),∴实数m 的取值范围是(-∞,2].数学寒假作业(四)测试范围:简易逻辑使用日期:腊月二十五 测试时间:120分钟一、选择题(本大题共12小题,每小题5分,共60分.在每小题给出的四个选项中,只有一项是符合要求的)1.下列语句中是命题的是( )A .周期函数的和是周期函数吗?B .sin 45°=1C .x 2+2x -1>0 D .梯形是不是平面图形呢?2.在命题“若抛物线y =ax 2+bx +c 的开口向下,则{x |ax 2+bx +c <0}≠∅”的逆命题、否命题、逆否命题中结论成立的是( )A .都真B .都假C .否命题真D .逆否命题真3.有下述说法:①a >b >0是a 2>b 2的充要条件;②a >b >0是1a <1b 的充要条件;③a>b >0是a 3>b 3的充要条件.则其中正确的说法有( )A .0个B .1个C .2个D .3个 4.下列说法中正确的是( )A .一个命题的逆命题为真,则它的逆否命题一定为真B .“a >b ”与“a +c >b +c ”不等价C .“a 2+b 2=0,则a ,b 全为0”的逆否命题是“若a ,b 全不为0, 则a 2+b 2≠0”D .一个命题的否命题为真,则它的逆命题一定为真5.(2013·广州一模)“m <2”是“一元二次不等式x 2+mx +1>0的解集为R ”的( ) A .充分不必要条件 B .必要不充分条件 C .充要条件 D .既不充分也不必要条件6.已知条件p :|x +1|>2,条件q :5x -6>x 2,则非p 是非q 的( ) A .充分不必要条件 B .必要不充分条件 C .充要条件 D .既不充分也不必要条件 7.有下列四个命题:①“若x +y =0, 则x ,y 互为相反数”的逆否命题; ②“全等三角形的面积相等”的否命题;③“若q ≤1,则x 2+2x +q =0有实根”的逆否命题; ④“不等边三角形的三个内角相等”逆命题. 其中真命题为( )A .①②B .②③C .①③D .③④8.已知命题p :若x ∈N *,则x ∈z .命题q :∃x 0∈R ,⎝ ⎛⎭⎪⎫12x 0-1=0.则下列命题为真命题的是( )A .非pB .p ∧qC .非p ∨qD .非p ∨非q 9.(2014·江西卷)下列叙述中正确的是( )A .若a ,b ,c ∈R ,则“ax 2+bx +c ≥0”的充分条件是“b 2-4ac ≤0” B .若a ,b ,c ∈R ,则“ab 2>cb 2”的充要条件是“a >c ”C .命题“对任意x ∈R ,有x 2≥0”的否定是“存在x ∈R ,有x 2≥0”D .l 是一条直线,a ,β是两个不同的平面,若l ⊥α,l ⊥β,则α∥β10.已知命题p :∀x ∈[1,2],x 2-a ≥0,命题q :∃x 0∈R ,x 20+2ax 0+2-a =0.若命题“p ∧q ”是真命题,则实数a 的取值范围是( )A .a ≤-2或a =1B .a ≤-2或1≤a ≤2C .a ≥1D .-2≤a ≤111.下列命题中的假命题是( )A .∀x >0且x ≠1,都有x +1x >2B .∀a ∈R ,直线ax +y =a 恒过定点(1,0)C .∀φ∈R ,函数y =sin(x +φ)都不是偶函数D .∀m ∈R ,使f (x )=(m -1)·xm 2-4m +3是幂函数,且在(0,+∞)上单调递减 12.已知命题p :∀x ∈[1,2],x 2-a ≥0,命题q :∃x 0∈R ,x 20+2ax 0+2-a =0.若命题“p ∧q ”是真命题,则实数a 的取值范围是( )A .a ≤-2或a =1B .a ≤-2或1≤a ≤2C .a ≥1D .-2≤a ≤1二、填空题(本大题共4小题,每小题5分,共20分.将正确答案填在题中的横线上) 13.命题:“若a ·b 不为零,则a ,b 都不为零”的逆否命题是________________________________________________________________________.14.用“充分、必要、充要”填空:①p∨q为真命题是p∧q为真命题的__________条件;②非p为假命题是p∨q为真命题的__________条件;③A:|x-2|<3,B:x2-4x-15<0,则A是B的________条件.15.命题“ax2-2ax-3>0不成立”是真命题,则实数a的取值范围是__________.16.若“x2>1”是“x<a”的必要不充分条件,则a的最大值为______.三、解答题(本大题共6小题,共70分. 解答应写出必要的文字说明、证明过程或演算步骤)17.(10分)对于下述命题p,写出“非p”形式的命题,并判断“p”与“非p”的真假:(1)p:91∈(A∩B)(其中全集U=N*,A={x|x是质数},B={x|x是正奇数});(2)p:有一个素数是偶数;(3)p:任意正整数都是质数或合数;(4)p:三角形有且仅有一个外接圆.18.(12分)写出命题“已知a,b∈R,若关于x的不等式x2+ax+b≤0有非空解集,则a2≥4b”的逆命题,并判断其真假.19.(12分)已知方程x2+(2k-1)x+k2=0,求使方程有两个大于1的实数根的充要条件.20.(12分)已知a >0,a ≠1,设p :函数y =log a (x +3)在(0,+∞)上单调递减,q :函数y =x 2+(2a -3)x +1的图象与x 轴交于不同的两点.如果p ∨q 真,p ∧q 假,求实数a 的取值范围.21.(12分)设命题p :实数x 满足x 2-4ax +3a 2<0,其中a >0,命题q :实数x 满足⎩⎪⎨⎪⎧x 2-x -6≤0,x 2+2x -8>0. (1)若a =1,且p ∧q 为真,求实数x 的取值范围; (2)非p 是非q 的充分不必要条件,求实数a 的取值范围.家长签字:日期:数学寒假作业(四)答案1、B 解析:可以判断真假的陈述句.2、D 解析:原命题是真命题,所以其逆否命题也为真命题.3、A 解析:①a >b >0⇒a 2>b 2,仅仅是充分条件;②a >b >0⇒1a <1b ,仅仅是充分条件;③a >b >0⇒a 3>b 3,仅仅是充分条件.4、D 解析:否命题和逆命题是互为逆否命题,有着一致的真假性.5、B 解析:一元二次不等式x 2+mx +1>0的解为m ∈(-2,2),则m <2只是其必要不充分条件.6、A 解析:非p :|x +1|≤2,-3≤x ≤1,非q :5x -6≤x 2,x 2-5x +6≥0,x ≥3或x ≤2,非p ⇒非q ,充分不必要条件. 7、C 解析:若x +y =0,则x ,y 互为相反数,为真命题,则逆否命题也为真;“全等三角形的面积相等”的否命题为“不全等三角形的面积不相等” 为假命题;若q ≤1⇒4-4q ≥0,即Δ=4-4q ≥0,则x 2+2x +q =0有实根,为真命题.“不等边三角形的三个内角相等”逆命题为“三个内角相等的三角形是不等边三角形”,为假命题.8、D 解析: 显然命题p 为真;因为对∀x ∈R ,都有⎝ ⎛⎭⎪⎫12x -1>0,所以命题q 为假,所以非q 为真,由“或”“且”“非”命题的真值表知D 正确.9、D 解析:由于“若b 2-4ac ≤0,则ax 2+bx +c ≥0”是假命题,所以“ax 2+bx +c ≥0”的充分条件不是“b 2-4ac ≤0”,A 错;∵ab 2>cb 2,且b 2>0,∴a >c .而a >c 时,若b 2=0,则ab 2>cb 2不成立,由此知“ab 2>cb 2”是“a >c ”的充分不必要条件,B 错;“对任意x ∈R ,有x 2≥0”的否定是“存在x ∈R ,有x 2<0”,C 错;由l ⊥α,l ⊥β,则a ∥β,可得α∥β,理由是:垂直于同一条直线的两个平面平行,D 正确.10、A 解析:∀x ∈[1,2],x 2-a ≥0,即a ≤x 2, 当x ∈[1,2]时恒成立,∴a ≤1.∃x 0∈R ,x 20+2ax 0+2-a =0, 即方程x 2+2ax +2-a =0有实根,∴Δ=4a 2-4(2-a )≥0,∴a ≤-2,或a ≥1.又p ∧q 为真,故p ,q 都为真,∴⎩⎪⎨⎪⎧a ≤1,a ≤-2或a ≥1.∴a ≤-2或a =1.11、C 解析:当x >0时,x +1x ≥2x ·1x =2,∵x ≠1,∴x +1x >2,故A 为真命题;将(1,0)代入直线ax +y =a 成立,B 为真命题;当φ=π2时,函数y =sin ⎝ ⎛⎭⎪⎫x +π2是偶函数,C 为假命题;当m =2时,f (x )=x -1是幂函数,且在(0,+∞)上单调递减,∴D 为真命题,故选C.12、A 解析:∀x ∈[1,2],x 2-a ≥0,即a ≤x 2, 当x ∈[1,2]时恒成立,∴a ≤1. ∃x 0∈R ,x 20+2ax 0+2-a =0,即方程x 2+2ax +2-a =0有实根,∴Δ=4a 2-4(2-a )≥0,∴a ≤-2,或a ≥1.又p ∧q 为真,故p ,q 都为真,∴⎩⎪⎨⎪⎧a ≤1,a ≤-2,a ≥1. ∴a ≤-2,或a =1.13、答案:若a ,b 至少有一个为零,则a ·b 为零 14、答案:①必要 ②充分 ③充分15、解析:ax 2-2ax -3≤0恒成立,当a =0时,-3≤0成立;当a ≠0时,⎩⎪⎨⎪⎧a <0,Δ=4a 2+12a ≤0, 得-3≤a <0.∴-3≤a ≤0.答案:[-3,0]16、解析:由x 2>1得x <-1或x >1,又“x 2>1”是“x <a ”的必要不充分条件,知由“x <a ”可以推出“x 2>1”,反之不成立,所以a ≤-1,即a 的最大值为-1.答案:-117、解析:(1)非p :91∉A ,或91∉B ;p 真,非p 假. (2)非p :每一个素数都不是偶数;p 真,非p 假.(3)非p :存在一个正整数不是质数且不是合数;p 假,非p 真.(4)非p :存在一个三角形有两个及其以上的外接圆或没有外接圆;p 真,非p 假.18、解析:逆命题为:“已知a ,b ∈R ,若a 2≥4b ,则关于x 的不等式x 2+ax +b ≤0有非空解集”.由a 2≥4b 知,Δ=a 2-4b ≥0.这说明抛物线y =x 2+ax +b 与x 轴有交点,那么x 2+ax +b ≤0必有非空解集.故逆命题是真命题.19、解析:令f (x )=x 2+(2k -1)x +k 2,方程有两个大于1的实数根⇔⎩⎪⎨⎪⎧Δ=(2k -1)2-4k 2≥0,-2k -12>1,f (1)>0,即k <-2,所以其充要条件为k <-2.20、解析:对于命题p :当0<a <1时,函数y =log a (x +3)在(0,+∞)上单调递减. 当a >1时,函数y =log a (x +3)在(0,+∞)上单调递增,所以如果p 为真命题,那么0<a <1.如果p 为假命题,那么a >1.对于命题q :如果函数y =x 2+(2a -3)x +1的图象与x 轴交于不同的两点,那么Δ=(2a -3)2-4>0,即4a 2-12a +5>0⇔a <12,或a >52.又∵a >0,所以如果q 为真命题,那么0<a <12或a >52.∴a 的取值范围是⎣⎢⎡⎭⎪⎫12,1∪⎝ ⎛⎭⎪⎫52,+∞. 21、解析:(1)由x 2-4ax +3a 2<0,的(x -3a )(x -a )<0. 又a >0,所以a <x <3a ,当a =1时,1<x <3,即p 为真命题时,1<x <3.由⎩⎪⎨⎪⎧x 2-x -6≤0,x 2+2x -8>0, 解得⎩⎪⎨⎪⎧-2≤x ≤3,x <-4或x >2, 即2<x ≤3.所以q 为真时,2<x ≤3.若p ∧q 为真,则⎩⎪⎨⎪⎧1<x <3,2<x ≤3⇔2<x <3, 所以实数x 的取值范围是(2,3).(2)∵非p 是非q 的充分不必要条件,∴q 是p 的充分不必要条件,则有(2,3](a ,3a ).于是满足⎩⎨⎧a ≤2,3a >3,解得1<a ≤2,故所求a 的取值范围是(1,2].数学寒假作业(五)测试范围:圆锥曲线使用日期:腊月二十七 测试时间:120分钟一、选择题(本大题共12小题,每小题5分,共60分.在每小题给出的四个选项中,只有一项是符合要求的)1.椭圆x 24+y 2=1的两个焦点为F 1、F 2,过F 1作垂直于x 轴的直线与椭圆相交,一个交点为P ,则|PF 2→| =( )A.32B. 3C.72 D .42.抛物线的顶点和椭圆x 225+y 29=1的中心重合,抛物线的焦点和椭圆x 225+y 29=1的右焦点重合,则抛物线的方程为( )A .y 2=16xB .y 2=8xC .y 2=12xD .y 2=6x3.双曲线x 2-y 2m =1的离心率大于2的充分必要条件是( )A .m >12 B .m ≥1 C .m >1 D .m >24.已知双曲线x 2a 2-y 2b 2=1(a >0,b >0)的一条渐近线方程是y =3x ,它的一个焦点在抛物线y 2=24x 的准线上,则双曲线的方程为( )A.x 236-y 2108=1B.x 29-y 227=1C.x 2108-y 236=1D.x 227-y 29=15.(2013·惠州一调)已知实数4,m ,9构成一个等比数列,则圆锥曲线x 2m +y 2=1的离心率为( )A.306B.7C.306或7D.56或76.在y =2x 2上有一点P ,它到A (1,3)的距离与它到焦点的距离之和最小,则点P 的坐标是( )A .(-2,1)B .(1,2)C .(2,1)D .(-1,2)7.已知F 1(-1,0),F 2(1,0)是椭圆C 的两个焦点,过F 2且垂直x 轴的直线交C 于A ,B 两点,且|AB |=3,则C 的方程为( )A.x 22+y 2=1 B.x 23+y 22=1 C.x 24+y 23=1 D.x 25=y 24=18.(2013·新课标全国卷Ⅰ)O 为坐标原点,F 为抛物线C :y 2=42x 的焦点,P 为C 上一点,若|PF |=42,则△POF 的面积为( )A .2B .2 2C .2 3D .49.动圆的圆心在抛物线y 2=8x 上,且动圆恒与直线x +2=0相切,则动圆必过点( )A .(4,0)B .(2,0)C .(0,2)D .(0,-2)10.已知F 是抛物线y =14x 2的焦点,P 是该抛物线上的动点,则线段PF 中点的轨迹方程是( )A .x 2=y -12 B .x 2=2y -116 C .x 2=2y -1 D .x 2=2y -211.椭圆x 225+y 29=1上一点P 到两焦点的距离之积为m ,则m 取最大值时,P 点坐标是( )A .(5,0)或(-5,0) B.⎝ ⎛⎭⎪⎫52,332或⎝ ⎛⎭⎪⎫52,-332C .(0,3)或(0,-3) D.⎝ ⎛⎭⎪⎫532,32或⎝ ⎛⎭⎪⎫-532,3212.已知F 1,F 2是双曲线x 2a 2-y 2b 2=1(a >b >0)的左、右焦点,P 为双曲线左支上一点,若|PF 2|2|PF 1|的最小值为8a ,则该双曲线的离心率的取值范围是( )A .(1,3)B .(1,2)C .(1,3]D .(1,2]二、填空题(本大题共4小题,每小题5分,共20分.将正确答案填在题中的横线上) 13.抛物线y 2=8x 上一个点P (P 在x 轴上方)到焦点的距离是8,此时P 点的坐标是________.14.与椭圆x 24+y 23=1具有相同的离心率且过点(2,-3)的椭圆的标准方程是____________.15.若直线y =32x 与双曲线x 2a 2-y 2b 2=1(a >0,b >0)的交点在实轴上的射影恰好为双曲线的焦点,则双曲线的离心率是________.16.抛物线y 2=x 上存在两点关于直线y =m (x -3)对称,则m 的范围是_________________.三、解答题(本大题共6小题,共70分. 解答应写出必要的文字说明、证明过程或演算步骤)17.(10分)求适合下列条件的双曲线的标准方程: (1)焦点在 x 轴上,虚轴长为12,离心率为 54; (2)顶点间的距离为6,渐近线方程为y =±32x .18.(12分) 已知椭圆C 的焦点F 1(-22,0)和F 2(22,0),长轴长为6,设直线y =x +2交椭圆C 于A 、B 两点,求线段AB 的中点坐标.19.(12分)中心在原点,焦点在x 轴上的一个椭圆与一双曲线有共同的焦点F 1,F 2,且|F 1F 2|=213,椭圆的长半轴与双曲线的实半轴之差为4,离心率之比为3∶7.求这两条曲线的方程.20. (12分)已知动点P 与平面上两定点A (-2,0)、B (2,0)连线的斜率的积为定值-12.(1)试求动点P 的轨迹方程C ;(2)设直线l :y =kx +1与曲线C 交于M 、N 两点,当|MN |=423时,求直线l 的方程.21.(12分)设椭圆C 1:x 2a 2+y 2b 2=1(a >b >0),抛物线C 2:x 2+by =b 2.(1)若C 2经过C 1的两个焦点,求C 1的离心率;(2)设A (0,b ),Q ⎝ ⎛⎭⎪⎫33,54b ,又M ,N 为C 1与C 2不在y 轴上的两个交点,若△AMN 的垂心为B ⎝ ⎛⎭⎪⎫0,34b ,且△QMN 的重心在C 2上,求椭圆C 1和抛物线C 2的方程.22.(12分)已知椭圆x 2a 2+y 2b 2=1(a >b >0)的离心率e =63.过点A (0,-b )和B (a ,0)的直线与原点的距离为32. (1)求椭圆的方程;(2)已知定点E (-1,0),若直线y =kx +2(k ≠0)与椭圆交于C ,D 两点,问:是否存在k 的值,使以CD 为直径的圆过E 点,请说明理由.家长签字:日期:数学寒假作业(五)答案1、C2、A3、C 解析:由e 2=⎝ ⎛⎭⎪⎫c a 2=1+m 1=1+m >2,m >1.4、B5、C6、B7、C 解析:依题意可设椭圆的方程为x 2a 2+y 2b 2=1(a >b >0),则A ⎝ ⎛⎭⎪⎫1,b 2a ,B ⎝ ⎛⎭⎪⎫1,-b 2a ,又|AB |=b 2a -⎝ ⎛⎭⎪⎫-b 2a =2b 2a =3,∴2b 2=3a .又a 2-b 2=c 2=1,∴a =2,b = 3.故C 的方程为x 24+y 23=1.8、C 解析:设P (a ,b )为抛物线上在第一象限内的点,则a +2=42,得a =32,因为点P (a ,b )在抛物线上,所以b =26,所以S △POF =12×2×26=23,故选C.9、B 解析:直线x +2=0是抛物线的准线,又动圆圆心在抛物线上,由抛物线的定义知,动圆必过抛物线的焦点(2,0).10、C 解析:由y =14x 2⇒x 2=4y ,焦点F (0,1),设PF 中点Q (x ,y )、P (x 0,y 0), 则⎩⎪⎨⎪⎧2x =0+x 0,2y =1+y 0,4y 0=x 20,∴x 2=2y -1. 11、C 解析:|PF 1|+|PF 2|=2a =10,∴|PF 1|·|PF 2|≤⎝ ⎛⎭⎪⎫|PF 1||PF 2|22=25. 当且仅当|PF 1|=|PF 2|=5时,取得最大值,此时P 点是短轴端点,故选C.12、C 解析:|PF 2|2|PF 1|=(|PF 1|2a )2|PF 1|=|PF 1|+4a 2|PF 1|+4a ≥8a ,当|PF 1|=4a 2|PF 1|,即|PF 1|=2a 时取等号. 又|PF 1|≥c -a ,∴2a ≥c -a .∴c ≤3a ,即e ≤3.∴双曲线的离心率的取值范围是(1,3]. 13、答案:()6,4314、答案:x 28+y 26=1或3y 225+4x 225=1 15、答案:216、解析:设抛物线上两点A (x 1,y 1),B (x 2,y 2)关于直线y =m (x -3)对称,A ,B 中点M (x ,y ),则当m =0时,有直线y =0,显然存在点关于它对称.当m ≠0时,⎩⎪⎨⎪⎧y 21=x 1,y 22=x 2⇒y 1-y 2x 1-x 2=1y 1+y 2=12y =-1m ,所以y =-m 2,所以M 的坐标为(52,-m 2),∵M 在抛物线内,则有52>(m2)2,得-10<m <10且m ≠0,综上所述,m ∈(-10,10).答案:(-10,10)17、解析:(1)焦点在x 轴上,设所求双曲线的方程为x 2a 2-y 2b 2=1.由题意,得⎩⎪⎨⎪⎧2b =12,c a =54,b 2=c 2-a 2.解得a =8,b =6,c =10.所以焦点在x 轴上的双曲线的方程为x 264-y 236=1.(2)当焦点在x 轴上时,设所求双曲线的方程为x 2a 2-y 2b 2=1由题意,得⎩⎪⎨⎪⎧2a =6,b a =32.解得a =3,b =92.所以焦点在x 轴上的双曲线的方程为 x 29-y 2814=1.同理可求当焦点在y 轴上双曲线的方程为y 29-x 24=1. 故所求双曲线的方程为x 29-y 2814=1或y 29-x 24=1.18、解析:由已知条件得椭圆的焦点在x 轴上,其中c =22,a =3,从而b =1,所以其标准方程是 x 29+y 2=1.联立方程组⎩⎪⎨⎪⎧x 29+y 2=1,y =x +2,消去y 得,10x 2+36x +27=0.设A (x 1,y 1),B (x 2,y 2),AB 线段的中点为M (x 0,y 0),那么:x 1+x 2=-185,x 0=x 1+x 22=-95.所以y 0=x 0+2=15.也就是说线段AB 的中点坐标为⎝ ⎛⎭⎪⎫-95,15.19、解析:设椭圆的方程为x 2a 21+y 2b 21=1,双曲线的方程为 x 2a 22-y 2b 22=1,半焦距c =13,由已知得:a 1-a 2=4,c a 1∶c a 2=3∶7,解得:a 1=7,a 2=3.所以:b 21=36,b 22=4,故所求两条曲线的方程分别为:x 249+y 236=1 ,x 29-y 24=1.20、解析:(1)设点P (x ,y ),则依题意有y x +2·yx -2=-12,整理得x 22+y 2=1.由于x ≠±2,所以求得的曲线C 的方程为x 22+y 2=1(x ≠±2).(2)联立方程组⎩⎪⎨⎪⎧x 22+y 2=1,y =kx +1,消去y 得:(1+2k 2)x 2+4kx =0.解得x 1=0, x 2=-4k1+2k 2(x 1,x 2分别为M ,N 的横坐标).由|MN |=1+k 2|x 1-x 2|=1+k 2⎪⎪⎪⎪⎪⎪4k 1+2k 2=432,解得:k =±1.所以直线l 的方程x -y +1=0或x +y -1=0.。
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
第一部分 恒定电流 1.(2016·全国卷Ⅱ,17)阻值相等的四个电阻、电容器C及电池E(内阻可忽略)连接成如图所示电路。开关S断开且电流稳定时,C所带的电荷量为Q1;闭合开关S,电流再次稳定后,C所带的电荷量为Q2。Q1与Q2的比值为( ) A.25 B.12 C.35 D.23
2.(2014·新课标全国卷Ⅱ,22)在伏安法测电阻的实验中,待测电阻Rx约为200 Ω,电压表V的内阻约为2 kΩ,电流表A的内阻约为10 Ω,测量电路中电流表
的连接方式如图(a)或图(b)所示,结果由公式Rx=UI计算得出,式中U与I分别为电压表和电流表的示数。若将图(a)和图(b)中电路测得的电阻值分别记为Rx1
和Rx2,则__________(填“Rx1”或“Rx2”)更接近待测电阻的真实值,且测量值
Rx1__________(填“大于”“等于”或“小于”)真实值,测量值Rx2__________(填“大于”“等于”或“小于”)真实值。 3.(2016·北京理综,19)某兴趣小组探究用不同方法测定干电池的电动势和内阻,他们提出的实验方案中有如下四种器材组合。为使实验结果尽可能准确,最不可取的一组器材是( ) A.一个安培表、一个伏特表和一个滑动变阻器 B.一个伏特表和多个定值电阻 C.一个安培表和一个电阻箱 D.两个安培表和一个滑动变阻器 4.(2016·江苏单科,8)(多选)如图所示的电路中,电源电动势为12 V,内阻为2 Ω,四个电阻的阻值已在图中标出,闭合开关S,下列说法正确的有( ) A.路端电压为10 VB.电源的总功率为10 W C.a、b间电压的大小为5 VD.a、b间用导线连接后,电路的总电流为1 A 5.(2015·北京理综,19)如图所示,其中电流表A的量程为0.6A,表盘均匀划分为30个小格,每一小格表示0.02 A;R1的阻值等于电流表内阻的12;R2的阻值等于电流表内阻的2倍。若用电流表A的表盘刻度表示流过接线柱1的电流值,则下列分析正确的是( ) A.将接线柱1、2接入电路时,每一小格表示0.04 A B.将接线柱1、2接入电路时,每一小格表示0.02 A C.将接线柱1、3接入电路时,每一小格表示0.06 A D.将接线柱1、3接入电路时,每一小格表示0.01 A 6.(2015·浙江理综,14)下列说法正确的是( ) A.电流通过导体的热功率与电流大小成正比 B.力对物体所做的功与力的作用时间成正比 C.电容器所带电荷量与两极间的电势差成正比 D.弹性限度内,弹簧的劲度系数与弹簧伸长量成正比 7.(2015·安徽理综,17)一根长为L,横截面积为S的金属棒,其材料的电阻率为ρ,棒内单位体积自由电子数为n,电子的质量为m,电荷量为e。在棒两端加上恒定的电压时,棒内产生电流,自由电子定向运动的平均速率为v,则金属棒内的电场强度大小为( )
A.mv22eL B.mv2Sne C.ρnev D.ρevSL 8.(2014·天津理综,2)如图所示,电路中R1、R2均为可变电阻,电源内阻不能忽略,平行板电容器C的极板水平放置。闭合电键S,电路达到稳定时,带电油滴悬浮在两板之间静止不动。如果仅改变下列某一个条件,油滴仍能静止不动的是( ) A.增大R1的阻值 B.增大R2的阻值 C.增大两板间的距离 D.断开电键S
8 9 10 9.[2016·北京理综,21(1)]热敏电阻常用于温度控制或过热保护装置中。图1为某种热敏电阻和金属热电阻的阻值R随温度t变化的示意图。由图可知,这种热敏电阻在温度上升时导电能力________(选填“增强”或“减弱”);相对金属热电阻而言,热敏电阻对温度变化的响应更________(选填“敏感”或“不敏感”)。 10.(2015·山东理综,22)如图甲所示的电路中,恒流源可为电路提供恒定电流I0,R为定值电阻,电流表、电压表均可视为理想电表。某同学利用该电路研究滑动变阻器RL消耗的电功率。改变RL的阻值,记录多组电流、电压的数值,得到如图乙所示的U-I关系图线。 回答下列问题: (1)滑动触头向下移动时,电压表示数________(填“增大”或“减小”)。 (2)I0=________A。 (3)RL消耗的最大功率为________W(保留一位有效数字)。
第二部分 电学实验 1.(2016·全国卷Ⅱ,23)某同学利用图(a)所示电路测量量程为2.5 V的电压表的内阻(内阻为数千欧姆),可供选择的器材有:电阻箱R(最大阻值99 999.9 Ω),滑动变阻器R1(最大阻值50 Ω),滑动变阻器R2(最大阻值5 kΩ),直流电源E(电动势3 V),开关1个,导线若干。 实验步骤如下 ①按电路原理图(a)连接线路; ②将电阻箱阻值调节为0,将滑动变阻器的滑片移到与图(a)中最左端所对应的位置,闭合开关S; ③调节滑动变阻器,使电压表满偏; ④保持滑动变阻器滑片的位置不变,调节电阻箱阻值,使电压表的示数为2.00 V,记下电阻箱的阻值。 回答下列问题: (1)实验中应选择滑动变阻器________(填“R1”或“R2”)。
(2)根据图(a)所示电路将图(b)中实物图连线。 图(b) (3)实验步骤④中记录的电阻箱阻值为630.0 Ω,若认为调节电阻箱时滑动变阻器上的分压不变,计算可得电压表的内阻为________Ω(结果保留到个位)。 (4)如果此电压表是由一个表头和电阻串联构成的,可推断该表头的满刻度电流为________(填正确答案标号)。 A.100 μA B.250 μA C.500 μA D.1 mA 2.(2015·新课标全国卷Ⅰ,23)图(a)为某同学改装和校准毫安表的电路图,其中虚线框内是毫安表的改装电路。
(1)已知毫安表表头的内阻为100 Ω,满偏电流为1 mA;R1和R2为阻值固定的电阻。若使用a和b两个接线柱,电表量程为3 mA;若使用a和c两个接线柱,电表量程为10 mA。由题给条件和数据,可以求出R1=____ Ω,R2=______ Ω。 (2)现用一量程为3 mA、内阻为150 Ω的标准电流表对改装电表的3 mA挡进行校准,校准时需选取的刻度为0.5、1.0、1.5、2.0、2.5、3.0 mA。电池的电动势为1.5 V,内阻忽略不计;定值电阻R0有两种规格,阻值分别为300 Ω和1 000 Ω;滑动变阻器R有两种规格,最大阻值分别为750 Ω和3 000 Ω。则R0应选用
阻值为________ Ω的电阻,R应选用最大阻值为________ Ω的滑动变阻器。 (3)若电阻R1和R2中有一个因损坏而阻值变为无穷大,利用图(b)的电路可以判断出损坏的电阻。图(b)中的R′为保护电阻,虚线框内未画出的电路即为图(a)虚线框内的电路。则图中的d点应和接线柱________(填“b”或“c”)相连。判断依据是:_____________________________________________________________________。 3.(2015·新课标全国卷Ⅱ,23)电压表满偏时通过该表的电流是半偏时通过该表电流的两倍。某同学利用这一事实测量电压表的内阻(半偏法),实验室提供的器材如下: 待测电压表(量程3 V,内阻约为3 000 Ω),电阻箱R0(最大阻值为99 999.9 Ω),滑动变阻器R1(最大阻值100 Ω,额定电流2 A),电源E(电动势6 V,内阻不计),开关2个,导线若干。 (1)虚线框内为该同学设计的测量电压表内阻的电路图的一部分,将电路图补充完整。 (2)根据设计的电路,写出实验步骤: _____________________________________________________________________ ____________________________________________________________________。 (3)将这种方法测出的电压表内阻记为RV′,与电压表内阻的真实值RV相比,RV′________RV(填“>”、“=”或“<”),主要理由是_____________________________________________________________________。
4.(2016·江苏单科,10)小明同学通过实验探究某一金属电阻的阻值R随温度t的变化关系,已知该金属电阻在常温下的阻值约10 Ω,R随t的升高而增大,实验电路如图所示,控温箱用以调节金属电阻的温度。 实验时闭合S,先将开关K与1端闭合,调节金属电阻的温度,分别记下温度t1,t2,„和电流表的相应示数I1,I2,„。然后将开关K与2端闭合,调节电阻箱使电流表的示数再次为I1,I2,„,分别记下电阻箱相应的示数R1,R2,„。 (1)有以下两电流表,实验电路中应选用________。 A.量程0~100 mA,内阻约2 Ω B.量程0~0.6 A,内阻可忽略 (2)实验过程中,要将电阻箱的阻值由9.9 Ω调节至10.0 Ω,需旋转图中电阻箱的旋钮“a”、“b”、“c”,正确的操作顺序是________。 ①将旋钮a由“0”旋转至“1” ②将旋钮b由“9”旋转至“0” ③将旋钮c由“9”旋转至“0” (3)实验记录的t和R的数据见下表
请根据表中数据,在答题卡的方格纸上作出R-t图线。 由图线求得R随t的变化关系为R=________Ω。 5.[2016·天津理综,22(3)]某同学想要描绘标有“3.8 V,0.3 A”字样小灯泡L的伏安特性曲线,要求测量数据尽量精确、绘制曲线完整。可供该同学选用的器材除开关、导线外,还有: 电压表V1(量程0~3 V,内阻等于3 kΩ) 电压表V2(量程0~15 V,内阻等于15 kΩ) 电流表A1(量程0~200 mA,内阻等于10 Ω) 电流表A2(量程0~3 A,内阻等于0.1 Ω)
滑动变阻器R1(0~10 Ω,额定电流2 A) 滑动变阻器R2(0~1 kΩ,额定电流0.5 A) 定值电阻R3(阻值等于1 Ω) 定值电阻R4(阻值等于10 Ω) 定值电阻R5(阻值等于1 kΩ) 电源E(E=6 V,内阻不计) (1)请画出实验电路图,并将各元件字母代码标在该元件的符号旁。 (2)该同学描绘出的I-U图象应是下图中的________。 6.(2015·海南单科,11)某同学利用游标卡尺和螺旋测微器分别测量一圆柱体工件的直径和高度,测量结果如图(a)和(b)所示。该工件的直径为________cm,
温度t(℃) 20.0 40.0 60.0 80.0 100.0 阻值R(Ω) 9.6 10.4 11.1 12.1 12.8