《实验探究小车速度随时间变化的规律》课后练习1.doc

实验 探究小车速度随时间变化的规律 课后练习一、选择题1质量都是m的物体在水平面上运动，则在下图所示的运动图像中表明物体做匀速直线运动的图像的是（ ）2一枚自制的小火箭由地面竖直向上发射时的v-t图象如图所示，、则火箭上升到最高点的位置对应图中的 ao点 ba点 cb点 d.c点3甲乙两车从平直公路上的同一处向同一方向运动，其速度图像如图所示，则：a.开始阶段甲车在乙车的前面，20秒后乙车比甲车的速度大b.开始阶段乙车在甲车的前面，20秒后乙车比甲车的速度大c.20秒末乙车追上甲车d.在某一时刻乙车会追上甲车4有一物体作直线运动，其速度图线如图所示。那么，物体的加速度和速度方向相同的时间间隔t为 a只有0t2s b只有2st4sc0t2s和5st6sd0t2s和6st8s5在同一直线上运动的物体a和b的v-t图如下图所示，则由图可得a.a和b的运动方向相反 b.a和b的加速度方向相同c.a的加速度比b的加速度小 d.a的初速度比b的初速度小6某物体运动的v-t图像如图所示，下列说法中正确的是a物体在1s末和3s末时运动方向发生变化b物体在2s末回到出发点c物体在2s末和4s末时速度为零d物体始终向前运7如右图所示，横坐标是时间，下面说法正确的是a.若纵坐标表示位移，图像中物体一定做匀速直线运动b.若纵坐标表示速度，图像中物体一定做匀速直线运动c.若纵坐标表示位移，图像中直线的斜率就是物体的运动速度d.若纵坐标表示速度，图像中直线的斜率就是物体的运动加速度二、填空题t/sv/ms-151015010155甲乙8电磁或电火花打点计时器是一种使用_（填交流电或直流电）电的计时仪器，当电源频率是50hz时，它每隔 _时间打一次点。9如图所示甲、乙两物体运动的速度图象，由图可知乙物体运动的初速度是 m/s,加速度是 m/s2,经 s钟的时间，它们的速度大小相同。10汽车运动的速度-时间图像如下图所示，则汽车在50s末的加速度是_m/s2，在20s末的加速度是_m/s2，200s内的平均速度是_m/s。11、下图给出了汽车从a点出发到b点做直线运动的v-t图线，根据图线填空。（1）在0 s40s内汽车做_运动；加速度是_。（2）在40 s120 s内汽车做_运动；加速度是_（3）在120 s200 s内汽车做_运动；加速度是_；发生的位移是_。（4）由图中得到汽车从a点开始到速度大小为10 m/s 时所需的时间是_ _。三、计算题12、在用打点计时器测定做匀变速直线运动物体的加速度时，一定要每5 个点取一个记数点吗？ 参考答案1、b2、d3、d4、c5、abcd6、cd7、acd8、交流，0.02s9、 5 1 10 10、0 ,0.25, 1711、（1）匀加速直线；05 m/s2（2）匀速直线；0（3）匀减速直线；025 m/s2；800 m（4）20 s或160 s12、不一定。在测量时取记数点的根本目的是减少长度测量的相对误差，究竟如何取记数点，要根据打出的纸带上的点子之间的间隔以及清晰点子的总数来确定，在教材所规定的实验中，对小车的加速度没有加以限定，可以任意选择，我们可以适当选择加速度值，进而调整点子的间距和清晰点的个数，使我们在每5 个点取一个计数点的情况下得到78个记数点，这样使计数点间的时间间陋为0.1s，便于计算，有78个记数点也便于利用逐差法计算加速度的值，但在给定的运动中（例如自由落体），加速度值是确定的不能选择，打出的点子间的距离也是确定的，如何选记数点只能根据实际情况而定。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:hes working on