...2.4实验探究弹力和弹簧伸长的关系课后巩固训练(含解...

第课时实验一:探究弹力和弹簧伸长的关系 1.(2013巴中高三一模)在“探究弹力和弹簧伸长的关系”实验中,以下说法正确的是(ab)a.弹簧被拉伸时,不能超出它的弹性限度b.用悬挂钩码的方法给弹簧施加拉力,应保证弹簧位于竖直位置且处于平衡状态c.用直尺测量的弹簧长度即为弹簧的伸长量d.用几个不同的弹簧,分别测出几组拉力与伸长量,得出拉力与伸长量之比相等解析:由弹簧的使用常识知选项a、b正确,d错误;伸长量等于直尺测量的弹簧长度与弹簧原长之差,故选项c错.2.(2012合肥模拟)如图(甲)所示,一根弹簧一端固定在传感器上,传感器与电脑相连.当对弹簧施加变化的作用力(拉力或压力)时,在电脑上得到了弹簧形变量与弹簧产生的弹力大小的关系图像,如图(乙)所示.则下列判断不正确的是(a)a.弹簧产生的弹力和弹簧的长度成正比b.弹力增加量与对应的弹簧长度的增加量成正比c.该弹簧的劲度系数是200 n/md.该弹簧受到反向压力时,劲度系数不变解析:由题图(乙)知,fx是一个过原点的直线,k=200.10 n/m=200 n/m,可知选项a错,选项b、c、d正确.故选a.3.(2013宜宾第一次质检)某实验小组研究橡皮筋伸长与所受拉力的关系.实验时,将原长约200 mm的橡皮筋上端固定,在竖直悬挂的橡皮筋下端逐一增挂钩码(质量均为20 g),每增挂一个钩码均记下对应的橡皮筋伸长量;当挂上10个钩码后,再逐一把钩码取下,每取下一个钩码,也记下对应的橡皮筋伸长量.根据测量数据,作出增挂钩码和减挂钩码时的橡皮筋伸长量l与拉力f关系的图像如图所示.从图像中可以得出(d)a.增挂钩码时l与f成正比,而减挂钩码时l与f不成正比b.当所挂钩码数相同时,增挂钩码时橡皮筋的伸长量比减挂钩码时的大c.当所挂钩码数相同时,增挂钩码时橡皮筋的伸长量与减挂钩码时的相等d.增挂钩码时所挂钩码数过多,导致橡皮筋超出弹性限度解析:解题的关键在于弄清为什么两条图像会错开.实验中由于增挂钩码时所挂钩码数过多,导致橡皮筋超出弹性限度,弹簧无法及时恢复原长,两条图像才会出现差异.故选项d正确.4.为了测量某一弹簧的劲度系数,将该弹簧竖直悬挂起来,在自由端挂上不同质量的砝码.实验测出了砝码质量m与弹簧长度l的相应数据,其对应点已在图上标出.(g=9.8 m/s2)(1)作出ml的关系图线;(2)弹簧的劲度系数为n/m.解析: (1)根据所描的点画直线即可.(2)在直线上取相距较远的两点,横轴之差l为弹簧长度的变化量,纵轴之差m为砝码质量的变化量,根据k=fl=mgl=0.245 n/m.答案:(1)如图所示(2)0.245(0.2480.262均正确)5.(2012滁州模拟)为了探索弹力和弹簧伸长的关系,某同学选了甲、乙两根规格不同的弹簧进行测试,根据测得的数据绘出如图所示图像.(1)从图像上看,该同学没能完全按照实验要求做,从而使图像上端成为曲线,图像上端成为曲线是因为.(2)这两根弹簧的劲度系数分别为n/m和 n/m;若要制作一个精确程度较高的弹簧测力计,应选弹簧.(3)从上述数据和图线中分析,请对这个研究课题提出一个有价值的建议.建议:.解析:(1)在弹性范围内弹簧的弹力与形变量成正比,超过弹簧的弹性范围,则此规律不成立,所以所给的图像上端成为曲线,是因为形变量超过弹簧的弹性限度.(2)甲、乙两根弹簧的劲度系数分别为:k甲=f甲x甲=4610-2 n/m66.7 n/mk乙=f乙x乙=8410-2 n/m=200 n/m.要制作一个精确程度较高的弹簧测力计,应选用一定的外力作用时,弹簧的形变量大,故选甲弹簧.(3)建议:实验中钩码不能挂太多,控制在弹性限度内.答案:(1)形变量超过弹簧的弹性限度(2)66.7200甲(3)见解析以下是大学体验英语综合教程2(第三版)课后翻译答案unit11. 任何年满18岁的人都有资格投票。(be eligible to, vote)answer:anyone over the age of 18 is eligible to vote.2. 每学期开学前，这些奖学金的申请表格就会由学校发给每一个学生。(apply for, scholarship)answer:a form to apply for these scholarships is sent by the university to every student before the start of every semester.3. 遵照医生的建议，我决定戒烟。(on the advice of)answer:on the advice of my doctor, i decided to give up smoking.4. 公园位于县城的正中央。(be located in)answer:the park is located right in the center of town.5. 这所大学提供了我们所需的所有材料和设备。(facilities)answer:the university provides all the materials and facilities we desire.1. 他们花了多年的时间寻找内心的平静，但是收效甚微。(search for)answer:they spent many years searching for peace of mind, but with little success.2. 这种新药的成功研制已经使许多疾病的治疗发生了根本性的变革。(revolutionize)answer:the successful development of the new drug has revolutionized the treatment of many diseases.3. 由于这个国家的经济不景气，这家公司濒于破产。(on the edge of)answer:the company is on the edge of bankruptcy due to the economic depression in the country.4. 大学毕业后他成为了一名护士。他认为护士这一职业可能很有发展前途。(rewarding)answer:he became a nurse after college. he thought nursing could be a very rewarding career.5. 他像往常一样在文件上签了名。(just as)answer:he signed his name on the paper just as he has always done it.unit21. 警察们正忙着填写关于这场事故的各种表格。(fill out)answer:the policemen are busy fi lling out forms about the accident.2. 我想在还车之前把油箱加满。(fill up, fuel tank)answer:i want to fi ll up the fuel tank before returning the car.3. 如果你要投诉，最好遵循正确的程序。(follow the procedure)answer:if you want to make a complaint, youd better follow the correct procedure.4. 要不是约翰帮忙，我们绝不会这么快就完成实验。(without)answer:we couldnt have fi nished the experiment so soon without johns help.5. 暴风雨之后，岸边的人们焦急地搜索湖面以期发现小船的踪迹。(scan for)answer:after the storm, the people on the shore anxiously scanned the lake for any sign of the boat.1. 这个国家不大，但是在国际事务中它却发挥着重要作用。(play a role)answer:this country is not big, but it plays an important role in international affairs.2. 正是在我叔叔的帮助下，我得以克服困难，按时完成了任务。(it is . that)answer:it was with the help of my uncle that i overcame the difficulty and completed the assignment in time.3. 毕业时他决定留在北京，而他最好的朋友却选择了去西藏。(while)answer:while he decided to stay in beijing upon graduation, his best friend chose to go to tibet.4. 在这次校园英语演讲比赛中，我们班的玛丽获得了第三名。(come in)answer:in this campus english speaking contest, mary from our class came in third.5. 你应该知道学习弹钢琴需要有时间，有金钱，还要有毅力。(as well as)answer:you should know that it takes time, money as well as perseverance to learn to play the piano.unit31. 我发现量入为出地过日子越来越难了。(increasingly)answer:i find it increasingly difficult to live within my income.2. 现代政治家们都试图以电视讲话来影响普通百姓。(reach out)answer:modern politicians try to reach out to ordinary people in their tv speeches.3. 应该帮助学生对人生采取积极的态度。(adopt)answer:pupils should be helped to adopt a positive attitude to life.4. 希望全班同学参加这些讨论。(participate in)answer:everyone in the class is expected to participate in these discussions.5. 如果你犯了罪就必须受到惩罚。(crime)answer:if you commit a crime you must expect to be punished.1.儿子的死让老妇人变得麻木痴呆了。(numb)answer:the old woman was numbed by her sons death.2.身处所有这些烦恼之中，他依然能保持乐观。(in the midst)answer:in the midst of all troubles, he managed to remain cheerful.3. 虽有困难，他们还是设法坚持试验下去。(carry on)answer:they managed to carry on their experiments in spite of the difficulties.4.我们必须淘汰不合格的申请人。(weed out)answer:we have to weed out unqualified applicants.5. 医生要他减少抽烟。(cut down on)answer:the doctor told him to cut down on smoking.unit41.她在公共汽车站一直等到末班车进站。(come in)answer:she waited at the bus stop until the last bus came in.2.如果我们能帮得上忙，尽管和我们联系。(contact)answer:if there is any way we can be of assistance, please do not hesitate to contact us.3 .他需要多少船务人员才能使他的游艇航行？(crew, yacht)answer:how many crew does he need to sail his yacht?4 .虽然她的新书没有上一本好，但是我还是喜欢它。(not quite as)answer:i enjoyed her new book though its not quite as good as her last one.5 .我从未遇到过如此善良的人。(never before)answer:never before have i met such a kind person.1.公共汽车放慢速度并停下，让那位乘客上车。(slow down)answer:the bus slowed down and stopped to allow the passenger to get on board.2.许多车子都驶过去了，可是没有一辆愿意让我们搭便车。(roll by)answer:many vehicles rolled by, but no one offered us a ride.3 .请勿践踏草地。(get off)answer:please get off the grass.4.他按妻子的吩咐，一下班就去了市场。(make ones way)answer:he made his way to the marketplace right after work, as his wife had asked him to do.5 .值得庆幸的是，史蒂夫 (steve) 从自行车上摔下来时没有摔断骨头。(luckily)answer:luckily, steve didnt break any bones when he fell off his bike.unit51. 我们得把感情放在一边，从专业的角度来对待这件事。(from a professional standpoint)answer:we have to put aside our emotions and take it from a professional standpoint.2. 这部戏非常精彩，我很快就沉浸于激动人心的剧情之中。(lose oneself in)answer:the play was so wonderful that i soon lost myself in the excitement of it.3 .她没有什么爱好除非你把看电视也算是一种爱好。(unless)answer:she hasnt got any hobbies unless you call watching tv a hobby.4. 他说他是直接从市长本人那里得到这个信息的。(first-hand)answer:he said that he had got the information first-hand from the mayor himself.5 .既然你不能回答这个问题，我们最好问问别人。(since)answer:since you cant answer the question, perhaps wed better ask someone else.1. 由于公共汽车司机突然刹车，旅客们都不由自主地向前摔倒。(brake, pitch forward)answer:all the passengers pitched forward because the bus driver braked sharply.2. 这个协议将冲破对自由贸易设置的障碍。(break through, obstacle)answer:this agreement will break through the obstacles to free trade.3 .我刚放下叫出租车的电话，车就来了。(soon after)answer:the taxi arrived soon after i rang for it.4. 在过去，不管我什么时候到家，我父母总会等我。(no matter)answer:my parents always waited up for me no matter what time i got home.5 .由于没有一方愿意让步，两个公司之间的对话完全破裂了。(break down)answer:talks between the two companies completely broke down, because neither of them wanted to give in.unit61. 那件工作很难做，不过我想试试看。(have a shot)answer:its a difficult job, but id like to have a shot.2. 这是一本关于商务实践而非理论的书。(as opposed to)answer:this is a book about business practice as opposed to theory.3. 社会活动从未耽误她的学习。(in the way)answer:social activities never get in the way of her studies.4. 直到1911年人们才发现第一种维生素。(it is not until . that)answer:it was not until 1911 that the first of the vitamins was identified.5. 尽管年事已高，爷爷每天还帮忙做家务。(despite)answer:despite advanced years, grandpa helps do housework every day.1. 我们的婚姻很幸福，但我们也曾经历过许多坎坷。(ups and downs)answer:our marriage is happy but weve had many ups and downs.2. 许多外语教师常常在课堂上自顾自地讲得太多。(be inclined to)answer:many teachers of foreign languages are inclined to talk too much themselves in class.3. 那位著名演员每天早晨锻炼一小时以保持健康。(work out)answer:the famous actor keeps fit by working out for an hour every morning.4. 与他促膝长谈之后，她的怀疑消失了。(melt away)answer:after a long heart-to-heart talk with him, her suspicion melted away.5. 目前我们没有职位空缺，但我们肯定会记住您的申请。(keep in mind)answer:we have no vacancies now, but well certainly keep your application in mind.unit71. 他并不后悔说过的话，只是觉得他完全可以不用这种方式表达。(could have done)answer:he did not regret what he had said but felt that he could have expressed it differently.2. 我们最好等到12月14日。那时大卫已考完试，就能和我们一起去度假了。(will have done)answer:wed better wait till 14 december. david will have had his exam by then, so hell be able to go on holiday with us.3. 他正在做一个新项目，年底前必须完成。(work on)answer: