2019-2020年九年级下学期第4周小步训练
2019-2020最新九年级物理下学期第9周小步训练 苏科版word版
19．如图所示，闭合开关，发现电动机不能转动，此时电压表示数为0.2V，电流表示数为0.5A.调节滑动变阻器，使得电动机正常转动，此时流过电压表示数为2V，电流表示数为1A.则该电动机线圈的电阻是___ ___Ω，电动机正常转动时的输出机械功率为___ ___W，此时该电动机的效率是___ ___.
28．（9分）倪龙在“测量小灯泡的额定功率”时准备了如下器材：额定电压为6V的小灯泡、稳定电源（电压大约12V）、最大阻值为R0的滑动变阻器（R0已知）、电流表、电压表、开关各1个，导线若干.
（1）请用笔画线代替导线，将图甲电路连接完整；
（2）实验中在开关闭合前应该将滑动变阻器的滑片调至最___ ___（左/右）端；
（3）倪龙正确连接好电路后，闭合开关，移动滑动变阻器的滑片，发现小灯泡始终不亮，电压表有示数，电流表示数为0，经检查电表完好，则故障可能是___ ___；
（4）故障排除后，再次闭合开关，移动滑动变阻器的滑片到某一位置时，小灯泡正常发光，此时电流表的示数如图乙所示，则小灯泡的额定功率是___ ___W，此时小灯泡的电阻为___ ___Ω；
A．用热水洗烫干丝时通过热传递的方式增加了干丝的内能
B．切成细丝的干丝“藕断丝连”是由于分子间存在斥力
C．烫干丝香味四射说明分子在永不停息地做无规则运动
D．烫干丝的温度越高越能入味说明分子运动快慢与温度有关
2019-2020年九年级中考英语模拟试卷(四)含答案
2019-2020年九年级中考英语模拟试卷（四）含答案一、单项填空(共15小题；每小题1分，满分15分)从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
( ) 1．exciting news it is! Our government is doing something to stop the haze(雾霾)．A．What B．What an C．How D．How an( ) 2．Johnson was the first on the list of the famous stars because he was the richestthem．A．with B．in C．to D．among( ) 3．of the surface of the earth covered with water．A．Seven-tens；are B．Seven-tens：isC．Seven-tenths；is D．Seven-tenths；are( ) 4．The shop until 9 o’clock p.m．A．remains opened B．remains openC．continues opened D．continues open( ) 5．With the help of the Internet，news can every corner of the world．A．get B．arrive C．reach D．return( ) 6．You don’t know 1 want to see you again．It’s a year since I last saw you．A．how soon B．how long C．how often D．how much( ) 7．—Didn’t your．brother go to school by bike?—Yes，he did．But he walking to school now．A．used to；used to B．use to；used toC．used to；is used to D．use to；is used to( ) 8．Wlw not your teacher for advice when you don’t know theproblems?A．ask；what to do with B．to ask；how to deal withC．ask；what to deal with D．to ask；how to do with( ) 9．一Do you know much about the city?—Yes，I there three times．A．was B．have gone C．went D．have been( )10．I do not doubt win in the race．A．whether he will B．whether will he C．that he will D．that will he( )11．一How cool the iPhone 6 is!一In our shop it very well now．Get one before it out．A．sells；sells B．sells；is sold C．is sold；is sold D．is sold；sells ( )12．一To achieve our dream，we should study hard keep fit．一I agree with you．A．not；but B．not only；but alsoC．neither；nor D．either；or( )13．一How about climbing the hill?—I would rather along the river than the hill．I’m a bit tired．A．walk；climb B．walking；climbingC．walking；to climb D．walk；to climb( )14．Bob often says that swimming is than hiking in reducing weight，but healways spends more time on swimming．A．more useful B．1ess interestingC．1ess useful D．more interesting( )15．一Would you mind my opening the window?—A．1 would．B．1’m afraid it’s too windy．C．Yes，please go ahead．D．Sure．I’m going to close it soon．二、完形填空(共10小题；每小题1分，满分10分)先通读下面的短文，掌握其大意，然后在每小题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
最新人教新目标2019-2020学年九年级下学期英语Unit4能力综合训练
2019-2020学年九年级下学期英语Unit 4能力综合训练(时间：100分钟满分：100分)Ⅰ.单项选择。
(共10小题；每小题1分，计10分)1.There ________ a book and three pens on the floor.A．am B．is C．are D．were2.Shall we ________ to the park for a walk?A．go B．goes C．going D．went3.Nowadays China has made great achievements in many fields.We really___ our amazing China. A．take pride in B．take care of C．take an interest in D．take part in4.—Wow, a new cellphone, what a big surprise! Thanks, darling!—It's your birthday present.But please read the ________ carefully before you use it. A．information B．instructions C．invitations D．instruments5.—I passed my driving test yesterday.—Did you? ________A．Forget it!B．Congratulations! C．Thanks.D．Don't worry!6.—Could you tell me how to behave politely in public in the UK?—Yes.________，you should keep your voice down and always queue.A．After all B．First of all C．In all D．At all7.Are you good at ________ soccer?A．playing B．play C．plays D．to play8.—Thanks for ________me with my English.—It's my pleasure.I'm glad you've made such great progress.A．help B．to help C．helping D．helped9.As a teacher，I love being with my students.You can't imagine how much they ________ knowledge!A．are thirsty for B．are famous for C．are good for D．are responsible for10.He is the teacher ________ teaches us English.A．who B．how C．what D．whomⅠ.完形填空。
2022-2023学年人教版九年级英语第四单元周测(含答案)
九年级英语unit 4 限时训练一、选择填空从每题A、B、C、D四个选项中，选出一个最佳答案(15分)1. -I forgot to bring my ruler today.May I use ?-Of course.Here you are.A.myB.mineC.yourD.yours2. -Tina is very healthy. She often plays sports after school.-Yes. we exercise, it is for our body and mind.A.The more;the worseB.The more;the betterC.The fewer,the betterD.The less;the better3. -Mary, the TV please.Your dad is sleeping now.-OK,mom.A.tun upB.turn toC.turn onD.turn off4. -is it from the railway station to the city park?-Half an hour by bus.A.How longB.How soonC. How farD.How often5. Jinan becomes more and more beautiful. visitors come here to spend their holidays.A.Thousands ofB.Thousand ofC.ThousandsD.Thousand6. -I’ll have a test tomorrow. I feel nervous and can’t fall asleep, mom.-, my honey.I believe you’re the best.A.What a pityB.Have a good timeC.with pleasureD. Take it easy7.Tom,the umbrella with you. Look at the clouds.It’s going to rain!A.takingB.takesC.takeD.took8. -Do you know that our class won first prize in the Singing Competition?-Really? good news!A.HowB.What aC.What anD.What9. -Jeff, how long have you?-For two years.I have owned it since my twelfth birthday.A.had the watchB.got the ringC.borrowed the bookD.bought the bag10.-I wonder .-What about this Sunday?A.when will we go to the moviesB.where will we go to the moviesC.when we will go to the moviesD.how we will go the movies11.-Your younger brother used to be shy,didn't he?-2. But now he is outgoing and likes making friendsA.Yes,he wasB.Yes,he didC.No,he didn'tD.No,he wasn't12.-I feel a bit nervous because I'm going for interview.-Take it easy and all______best.A.an;aB.the;aC.an,theD.the;an13.Remember some useful tips to guard any possible danger around us.For example,never tell a stranger your QQ account password(密码).A.beyondB.againstC.overD.along14. -is your cousin like?-He is tall and thin.A.WhatB.HowC.WhoD.Which15. -You won't believe how beautiful the Wuyi Mountain is.-How I wish I could be there !A.in personB.in dangerC.in commonD. in public二、完形填空阅读短文，从每题A、B、C、D四个选项中，选出一个能填入文章中相应空白处的最佳答案。
2019-2020最新九年级物理下学期第5周小步训练 苏科版word版
22.电子式电能表表盘上标有“220V10(40)A”、“3200imp/(kW·h)”等字样.将一个标有“220V 100W”字样的用电器单独接在该电能表上，正常工作15min消耗的电能是kW·h，这段时间内电能表指示灯会闪烁次.
18.小明按照教材中“综合实践活动”的要求制作简易密度计.将吸管放到水中的情景如图（a）所示，测得浸入的长度为H；放到另一液体中的情景如图（b）所示，浸入的长度为h．用ρ液、ρ水分别表示液体和水的密度，ρ液、ρ水、h，及H的关系式是ρ液=．将简易密度计放到盐水中，浸入的长度为h′，则h′（＝/＜/＞）H,吸管放到水中与放到盐水中相比,浮力(变大/不变/变小).
⑷把凸透镜看作眼睛的晶状体，光屏看作视网膜．小明给“眼睛”戴上一副眼镜，使烛焰在“视网膜”上成一清晰的像，如图若取下眼镜，将蜡烛适当靠近透镜，光屏上重新得到了清晰的像，则小明所用的眼镜是（近视/远视）眼镜．
30.（4分）在“探究杠杆平衡条件”实验中，利用在杠杆两端挂钩码的方法做实验，
实验装置如图所示.
——教学资料参考参考范本——
2019-2020最新九年级物理下学期第5周小步训练 苏科版word版
______年______月______日
____________________部门
班级__________ 姓名___________ 学号_______ 得分________
题号
1
2
3
4
5
6
7
8
9
23.交通运输中，提供动力的机器有电动机、汽油机等.电动机的原理是；汽油机将内能转化为能,汽油机转速为2400r/min,则1s内做功次.
北京四中2019--2020学年九年级下学期阶段性统练数学试题
对于任意矩形ABCD，下面四个结论中，①存在无数个四边形MNPQ是平行四边形；②存在无数个四边形MNPQ是矩形；③存在无数个四边形MNPQ是菱形；④至少存在一个四边形MNPQ是正方形．所有正确结论的序号是______．
A． B． C． D．
2．下列四个图形是四所医科大学的校徽．其中校徽内部图案（不含文字）是轴对称图形的是（ ）
A． B． C． D．
3．用配方法解方程 ，方程应变形为（）
A． B．
C． D．
4．下列选项中，左边的平面图形能够折成右边封闭的立体图形的是( )
A． B．
C． D．
5．如果 ，且 ，那么代数式 的值为（）
三、解答题
17．计算： ．
18．解不等式组:
19．关于x的一元二次方程x2+2x﹣（n﹣1）＝0有两个不相等的实数根．
（1）求n的取值范围；
（2）若n为取值范围内的最小整数，求此方程的根．
20．如图，在△ABC中，∠ACB＝90°，D是BC边上的一点，分别过点A、B作BD、AD的平行线交于点E，且AB平分∠EAD.
A． B． C． D．
6．如图，AB为⊙O的直径，点C在⊙O上，若∠ACO＝50°，则∠B的度数为（）
A．60°B．50°C．40°D．30°
7．如图，数轴上A，B两点所表示的数互为倒数，则关于原点的说法正确的是（ ）
A．一定在点A的左侧B．一定与线段AB的中点重合
C．可能在点B的右侧D．一定与点A或点B重合
a．甲部门成绩的频数分布直方图如下（数据分成6组：40≤x＜50，50≤x＜60，60≤x＜70，70≤x＜80，80≤x＜90，90≤x≤100）
2019-2020学年第二学期外研版英语九年级下册module 4单元测试卷
2019-2020学年度第二学期外研版英语九年级下册Module 4单元测试卷一、单项选择(每小题1分，共20分)( )1．—the water was cold , Wei Qinggang jumped into it to save others.A．Although B．When C．If D．Because( )2．—Can we walk across the road now?—No, we . We have to wait until the light turns green.A．couldn’t B．needn’t C．shouldn’t D．mustn’t( )3．In order for the meeting, my sister forced herself to get up early this morning.A．not to be late B．not being late C．to be late D．being late( )4．—Can you swim, Julia? —No, I ________. ________ I can’t skate.A．can’t; And B．can; But C．can’t; But D．can; And( )5．— Remember the book to the library. — But I remembered it.A．to return; to return B．returning; to return C．returning; returning D．to return; returning ( )6．You shout out in class.A．can B．couldn't C．must D．mustn't( )7．—I didn't hear you come in just now. —That’s good. I tried the baby up.A．to wake B．not to wake C．waking D．walk( )8．I have to tell you.A．new something B．something new C．new anything D．anything new( )9．Do you have anything else me?A．tell B．tells C．to tell D．telling( )10．Mike, you play with fire. You burn yourself.A．won't; can't B．have got to; shouldn't C．don't have to; must D．mustn't; might( )11．You put the seatbelt（安全带）on before driving.A．can B．must C．would D．could( )12．—Must we do our homework first? —No, you___. You may have a rest first.A．mustn't B．needn't C．may not D．can't( )13．—the room before you go out. — 0K, Mum.A．Forget to clean B．Forget cleaning C．Remember to clean D．Remember cleaning ( )14．If you have any spare milk, could you give me ?A．a few B．few C．a little D．little( )15．A girl named Dong Xinyi looked after her disable father.A．three-years-old B．three-year-old C．three years old D．three year old( )16．Thank you for my grandpa when I was away.A．taking care B．looking at C．taking care of D．look after( )17．________ haburgers are junk food, many children still like them.A．If B．Unless C．Because D．Although( )18．— Mr Green isn't in at the moment. Would you like to ?— Yes. Please tell him tomorrow's meeting will be at 9:30.A．take a message B．ring again later C．call me back D．leave a message( )19．Tom was too tired after finishing his homework and he soon.A．sleep B．fell asleep C．sleeping D．to sleep( )20．—How many English words do you think I should know?—As many as you ______. Then you will find reading quite easy.A．will B．must C．can D．might二、完型填空(每小题1分，共10分)In a cold winter, a couple had to move out of their big house because of bankruptcy, The husband worked day and night but with low care of his wife. 21 she thought, "He doesn't love me any more, he just thinks about 22 work."One day, she wanted to take a 23 , but her husband stopped her at the door, "Let me take it first, OK?" "Why not let me first," she asked. "I was tired, you take it later, OK?" She was very sad.On a rainy day, she found nothing to do and turned 24 his computer. After a few minutes, her eyes were full of tears… it was his diary on the computer:Today, I was quite sad, she asked me 25 . I was always taking the shower first, and I said I was tired. She was unhappy. I wasn't as 26 as before! We moved to the small house and it was very cold. I 27 that if one person took the shower first, the room could get a little 28 . So I always 29 the bathroom first. When she took the shower, the temperature in the bathroom could get a little higher. I can't give her more, but 30 , I can give her 1℃ love.( )21．A．Because B．So C．Unless D．If( )22．A．my B．her C．his D．our( )23．A．walk B．shower C．look D．rest( )24．A．on B．up C．down D．off( )25．A．what B．when C．why D．how( )26．A．sad B．satisfied C．poor D．rich( )27．A．explained B．suggested C．found D．said( )28．A．cooler B．warmer C．hotter D．colder( )29．A．rushed into B．rushed out of C．waited outside D．stayed outside( )30．A．at most B．at first C．at last D．at least三、阅读理解(每小题2分，共40分)A(Renee-a beautiful princess; Broo-a blue bear; Nahloo-a magical place)When the Princess Renee heard about Broo, she came down from her castle. She found Broo while he was busy eating honey.“Mr. Bear,” the Princess said, “you are welcome in Nahloo. Here we share with each other. We don’t take things from each other.”Broo thought about it for a moment and realized that he had made a mistake. “Well,” he said, “maybe drinking all that milk wasn’t the best idea.”The Princess continued, “Mr. Bear, you can drink and eat, but you won’t feel good because you have never made any contribution to anyone else. I think you’ll find that it is better to be full in your heart, not just in your stomach.” After saying this, the Princess went back to the castle, leaving Broo alone.One day, Broo was going to take lots of cookies from the rabbits, then he remembered what the Princess said to him. So Broo decided not to eat the cookies. The rabbits were surprised and said, “Thank you for your kindness, Mr. Bear. Now these cookies will taste sweeter because they are given by you, my friend. If you like, come back tomorrow and we can have the cookies together.”Broo was filled with joy and went through the land. He gave back everything he had taken. In return, he received a promise from everyone to share their food with him. Broo was so delighted that he started dancing in the moonlight with the Princess as his partner.( )31．When the Princess Renee came down, Broo was _________.A．dancing with rabbits B．eating honey C．giving everything back D．having cookies( )32．In Nahloo, ___________.A．the Princess Renee stayed with Broo all the time B．everyone was happy to share with each otherC．Broo took a lot of cookies from rabbits D．Broo never realized his mistake( )33．Broo felt _________ after he gave the cookies back to the rabbits.A．sad B．surprised C．happy D．hungry( )34．The passage is probably from _______.A．an advertisement B．a tour guide C．an application D．a story book( )35．What can we learn from the passage ?A．It’s better to give than to receive.B．Every dog has its day.C．The early bird catches the worm. D．Many hands make light work.BBIPC would like to invite beekeepers to the World Bee Day Activities 9:00am-4:00 pm, Sunday, May 20th, 2018Landhill Hall, CornwallBees are now in danger and its number is going down every year largely because of human activity, while a third of the world's food production depends on this yellow and black insect（昆虫）and other pollinators（传授花粉者）.May 20th this year is the first World Bee Day. It was created last year by the UN, after Slovenia put forward the idea, to draw people's attention to the important role of bees and other pollinators in keeping the planet healthy.A day for all those who are interested in learning to improve the quality（质量）of their bees! A day also for those who want to know more about bee keeping!Bring your family with you and have fun! Let's celebrate everything connected with bees and the coming of spring！Activities for the whole family talks on bees/bee products for sale/wax（蜡）& candle-making lessons Bee Communication:Dr Gavin Ramsay will explain the dances of bees, telling you about what smart behaviors bees have.Cleaning beeswax & candle-making lessons: Classes will be given by Kate Black.Cafe: Lunch and tea/coffee/cakes are available at the cafe.These activities are held by BIPC, the Bee Improvement Program for Cornwall.Tickets are $ 8 for members of BIPC and $10 for non-members. Half price for a child.All the money will go to the City Bee Protection Project.Book your place by emailing bengreen @ hotmail. com.( )36．The danger that bees are facing is caused by .A．beekeepers B．food production C．human activity D．other pollinators( )37．The World Bee Day was created .A．to advise people to keep healthy B．to help beekeepers sell more bee productsC．to celebrate the coming of spring D．to make people know the importance of bees( )38．During the activities, you can learn all the following EXCEPT .A．to make a candle B．to improve the quality of beesC．to make tea and coffee D．to understand the dances of bees( )39．Bill, a member of BIPC, and his 5-year-old son will pay for tickets to the activities.A．10 dollars B．12 dollars C．16 dollars D．18 dollars( )40．The money from the sales of tickets .A．will be used to protect bees B．will make BIPC very richC．will be given to beekeepers D．will be spent on the celebrationsCOn April 2, we said goodbye to Tiangong I, China's first space lab. According to the China Manned Space Agency（中国载人航天）, Tiangong I re-entered the Earth's atmosphere（大气层）and some of its debris（碎片）fell into the South Pacific Ocean.There are many spacecraft（宇宙飞船）that are still in orbit（轨道）above the Earth. After finishing their trips, they will all re-enter the Earth's atmosphere like Tiangong I.There are two types of re-entries: controlled re-entry and uncontrolled re-entry.Some satellites and manned spacecraft come back to the Earth in a controlled re-entry. Experts calculate（计算）the path of the falling spacecraft and its speed. They can guide the spacecraft to fall in a chosen area.Some spacecraft may have problems while in space after a certain amount of time. These spacecraft come back in an uncontrolled re-entry. It is hard to tell when and where these spacecraft will fall until the last few hours. The US space station Skylab came back partially uncontrolled in 1979. Parts of the station fell in western Australia, but no one was hurt.During re-entry, most of the spacecraft will burn up while passing through the Earth's atmosphere. Only a small amount of the debris will reach the ground. The debris typically ends up falling into the ocean, China Daily reported. ( )41．The debris from Tiangong 1 .A．fell into the South Pacific Ocean B．fell in western AustraliaC．fell in the central part of the US D．fell into the North Pacific Ocean( )42．When the spacecraft finishes its trip, it will .A．burn up and disappear B．speed up and fly back to the EarthC．enter another orbit and stay in space D．re-enter the Earth's atmosphere( )43．From the passage, we know there are types of re-entries.A．one B．two C．three D．four( )44．Which of the following is TRUE about the US space station Skylab?A．It came back in a controlled re-entry. B．Some people were hurt by its debris.C．Parts of it fell in western Australia. D．It was directed to fall into the ocean.( )45．This story most probably comes from .A．a story book B．a movie review C．a science magazine D．a government reportDThere is a sign at a Korean university asking tourists not to step into the grass to take photos. The sign is not written in Korean or English; it is written in Chinese.These signs, and signs in other countries warning Chinese tourists about their behavior, have shamed many Chinese who worry about the image of the country.Over 70 million Chinese tourists made overseas trips last year and spent $102 billion, more than the $84 billion spent by American and German tourists. For many Chinese tourists, it was their first trip abroad and they didn't know about foreign ways. And some of these tourists took their bad habits from China with them.Wang Yang, a Chinese deputy prime minister (国务院副总理), said, "They (the tourists) speak loudly in public, carve words or numbers on tourist attractions, cross the road when the traffic lights are still red and spit anywhere. It damages(毁坏) the image of the Chinese people and has a very bad influence."Before you travel to a foreign country, it's important to learn some things about the country and its culture. You are guests in the country and it's important to respect(尊重) your hosts. As more and more Chinese visit foreign countries, their behavior will certainly change and those shameful signs will, hopefully, disappear.( )46．The sign at a Korean university is written in .A．Chinese B．English C．Korean( )47．How do many Chinese feel about the signs?A．Proud. B．Interested. C．Shameful.( )48．The underlined word "image" probably means " " in Chinese.A．形象B．热情C．财富( )49．The passage is written to .A．order the Korean university to clean up signs with Chinese wordsB．advise the overseas Chinese tourists to change their behaviorC．ask Chinese people not to spend too much money traveling abroad( )50．What would be the best title for the passage?A．Signs Shame Overseas Chinese Tourists B．Foreign Culture Makes Bad InfluenceC．Foreign Countries Attract Chinese Tourists四、根据中文提示填空(每小题1分，共5分)51．The old like wearing ______（舒适的）clothes.52．Don't listen to ______（个人的）music players while climbing.53．You mustn't ______（点燃）fires while climbing.54．The road to my hometown is very ______（光滑的）.55．A green school must include ______（教育）about environment.五、用适当的介词或者副词填空(每小题1分，共5分)56．We will set ______ ______ eight tomorrow morning.57．You mustn't go ______ ______ your own.58．We'll stop ______ noon ______ our picnic.59．Be careful ______ the knife.60．It's a straight path ______ the moment.六、用所给单词的正确形式填空(每小题1分，共10分)61．We were all excited after ______ (see) the film.62．The workers are tired. Let them stop ______ (have) a rest.63．We ______ (put) up the tent and went to sleep.64．I'm sorry to keep you ______ (wait) for half an hour.65．I remembered ______ (post) the letter for you last night.66．Drivers mustn't drive after ______ (drink).67．Your teacher are very ______ (worry) about you.68．We should play our part in ______ (clean) the classroom.69．Rubbish causes plants and fish ______ (die).70．______ (read) in bed is bad for your eyes.七、句型转换(每小题2分，共10分)71．The man had a terrible accident during the trip. (改为同义句)A terrible accident _______ ______ the man during the trip.72．My mother will be backin two hours. (对画线部分提问)______ ______will your mother be back?73．T he girl’s left leg was wounded. (改为同义句)The girl ______ _____ ______ in her left leg.74．Tina came to the office half an hour ago. (用for half all hour替换half all hour ago) Tina ______ _____ ______ ______ ______ for half an hour.75．His uncle left for Rizhao yesterday. (用in about three days改写句子)His uncle ______ _______ for Rizhao in about three days.八、完成句子(每小题2分，共10分)76．你必须小心落石。
2019-2020年九年级数学下第四周周测卷
2019-2020年九年级数学下第四周周测卷一.选择题:（每题4分,共20分）1.对于抛物线221x y -=下列说法正确的是----------------------------------（ ）A ．最大值为1；B ．最小值为1；C ．最大值为－2；；D ．最小值为－2；2.抛物线2228,5,41x y x y x y =-==共有的性质是--------------------------（ ）A ．开口方向相同B ．开口大小相同C ．当x ＞ 0时，y 随x 的增大而增大D ．对称轴相同3.抛物线()9232+--=x y 的顶点坐标是--------------------------- （ ）A ．(2，9)B ．(-2，9)C ．(2，-9)D ．(-2，-9)4. 抛物线y ＝x 2＋2x 的顶点在-------------------------------------------------------------------- ( )A.第一象限B.第二象限C.第三象限D.第四象限5. 函数231x y -=的图象通过怎样的平移，可得到函数3)2(312-+-=x y ---------( )A ．向左平移2个单位，再向下平移3个单位B ．向右平移2个单位，再向下平移3个单位C ．向左平移2个单位，再向上平移3个单位D ．向右平移2个单位，再向上平移3个单位二、填空题（每题4分,共20分）w W w.x K b 1. c o m6、二次函数2(1)2y x =-+的最小值是7. 二次函数23x y -=的图象开口 ，当x ＞ 0时，y 随x 的增大而8. 抛物线 y ＝－2x 2+1的对称轴是9. 将抛物线231x y =向左平移2个单位得到的抛物线的解析式为 ，10. 已知点A （2，1y ），B （4，2y ）在二次函数23x y -=的图象上，则1y 2y .三.解答题（11-14题每题7分，15-18题每题8分，共60分）11.用配方法求函数y ＝－x 2+8x 的顶点坐标12.用公式法求函数y ＝－3x 2+13x+1的最大值. 13. 求出抛物线y ＝2x 2－3x －5与两坐标轴的交点坐标 14.已知二次函数的图象的顶点坐标为（1，－6），且经过点（2，－8），求二次函数的解析式。
- 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)。
2019-2020年九年级下学期第4周小步训练姓名：班级：得分：一、选择题（每题2分，共24分）1．世界上第一个发现“电流周围存在磁场”的物理学家是A．牛顿 B．焦耳 C．奥斯特 D．法拉第2．下列有关声现象说法正确的是A．只有房主本人说出暗语时才能打开的“声纹门锁”，是依据声音的音调来识别的B．声和电磁波都能传递信息且都可以在真空中传播C．鼓乐声主要是由鼓内空气振动产生的D．中考期间学校路段禁止鸣喇叭，这是在声源处减弱噪声3．生活中很多热现象可以用学过的物理知识来解释，下列解释不正确的是A．天气很冷时窗户玻璃上出现冰花，这是由于凝固产生的B．湿衣服挂在阴凉处也能变干，是因为蒸发可以在任何温度下发生C．游泳后，刚从水中出来感觉比较冷，这是因为人身上的水分蒸发带走热量D．冰箱中取出的冰茶，过一会，容器的外壁附着一层小水珠，这是由于液化形成的4．光的世界变幻莫测、奥妙无穷．下列关于光现象的说法中，正确的是A．不同颜色的光在真空中传播的速度不同 B．雨后彩虹是由于光发生反射形成的C．海市蜃楼是由于光发生折射形成的D．日食和月食现象都是光沿直线传播和光的反射造成的5．下列实际应用中，主要从密度的角度考虑的是A．用纳米薄层和纳米点制造存储器等纳米电子器件B．用热值较高的燃料给火箭提供动力C．用塑料泡沫做电影场景中倒塌的“墙壁” D．用熔点较低的酒精制成能测量较低温度的寒暑表6．下列是发生在我们身边的常见物理现象，其中解释正确的是A．放在水平讲台上的书处于静止状态，因为它所受重力和支持力是一对平衡力B．推课桌时会运动，而不用力推就会停下来，说明力是物体产生运动的原因C．足球在空中沿曲线飞行，是因为受到重力和踢力的共同作用D．竖直上抛的足球飞行到最高处时，如果所有力突然消失，足球将保持匀速直线运动状态7．如图所示，物体G在竖直向上的拉力F的作用下，匀速上升0.2m．已知G=18N，F=10N．这一过程中，不能得到的结论是A．绳子自由端上升0.4m B．拉力F做功4JC．动滑轮重为2N D．该动滑轮的机械效率为90%8．如图，小球上下运动的过程中，下列分析不正确的是A．小球上下运动过程中，运动状态保持不变B．小球向下运动过程中，小球所受的重力对小球做功C．小球对弹簧施加拉力，弹簧对小球也施加拉力D．小球上下运动过程中，动能与势能不断相互转化9．某工厂通过一智能电路实现对甲、乙两机器工作状态的及时监控，机器都正常工作相当于形状断开，对应指示灯不亮，电铃不响；若任一机器出现故障相当于相应开关闭合，对应指示灯亮，电铃响．下列电路图中，符合要求的是10．如图所示的电路中，电源两端的电压保持不变．闭合开关S后，滑动变阻器的滑片P向右移动，下列说法中正确的是A．电流表A1与电流表A2的示数之和变小B．电压表V与电流表A2的示数之比保持不变C．电流表A1的示数变小，电压表V的示数变大D．电流表A2的示数不变，电压表V的示数不变11．我国科研人员研发了百米级第二代高温超导带材，使中国跻身该技术领域国际先进行列．假如所有导体都成了常温下的超导体，那么当用电器通电时，下列说法正确的是A．白炽灯仍然能发光B．电动机仍能转动C．电饭锅仍然能煮饭 D．电熨斗仍然能熨烫衣服12．为了研究光的传播，我们引入了“光线”，下列研究问题的方法与此相同的是A．通过小灯泡的亮暗，分辨电流的大小 B．通过磁感线研究磁场的分布C．通过水流来学习电流 D．通过扩散现象感知分子的运动二、填空题（共12小题每空格1分共25分）13．某校科技节上，老师将液氮“倒”在装有超导物质的磁悬浮列车模型上，由于液氮迅速汽化并热量，超导物质降温后变为超导体，使模型能悬浮在通电的环形轨道上．当模型在环形轨道上运行时，其运动状态（填“改变”或“不变”）．14．电视机遥控器可以发出不同的（选填“红外线”“紫外线”），来实现电视机的遥控；适当的（选填“红外线”“紫外线”）照射有助于人体合成维生素D．15．如图所示．建筑物在河中的“倒影”是由光的所形成的虚像，这些“倒影”看起来比建筑物本身“暗”一些，主要是因为有一部分光发生进入了水中．16．一列长200m的火车，以72km/h的速度匀速进入长为2km的隧洞，火车完全在洞中的时间是s，火车上乘客看见洞中的路灯在后退，乘客是以为参照物．17．美丽的鄂州“襟江抱湖枕名山”，素有“百湖之市”的美誉．市区及周边的湖泊，可以大大减弱该地区的“热岛效应”，这是利用了水的大的特性；春夏季节，漫步在洋澜湖畔，可以闻到阵阵的花香，从物理学的角度来讲，这是现象．18．图为某款雪地自行车，它的前轮被替换成滑雪板以增大受力面积，减小；后轮则被改装成履带，可以增大接触面的粗糙程度，增大，使该车便于雪地骑行。
19．小华质量为50kg，每只脚与地面的接触面积为200cm2，他双脚站立时对水平地面的压强为Pa，他走路时对水平地面的压强会．（选填“变大”、“变小”或“不变”）．（g=10N/k g）20．俗话说“瓜浮李沉”，意思是西瓜投入水中可以漂浮，李子投入水中会下沉．若西瓜的质量大于李子，则漂浮的西瓜受到的浮力下沉的李子受到的浮力，西瓜的密度李子的密度（选填“大于”、“小于”或“等于”）．21．电动自行车已成为大众化的一种交通工具，小乔对家里的电动自行车进行了测试，他骑车在平直的路面上由静止开始运动，获得如图所示的速度v和牵引力F随时间t变化的关系图象．已知匀速行驶时，电动机输入电压48V，输入电流5A，由图可知，7～12s电动自行车受到的摩擦力为N；电动自行车匀速行驶时，电能转化为机械能的效率为%．22．中国南海海底探明有大量的“可燃冰”，同等条件下，“可燃冰”完全燃烧放出的热量达到煤气的数十倍，说明“可燃冰”的________很大；以10倍的关系粗略计算，1kg“可燃冰”完全燃烧放出的热量可以使________kg的水从20℃加热至60℃．[q煤气=4.2×107J/kg，水的比热容c=4.2×103J/（kg•℃）]．23．有两个定值电阻，甲标有“10Ω 1Ａ”，乙标有“15Ω0.6Ａ”，把它们串联在同一电路中，总电阻是Ω；电路中允许通过的最大电流为A；电路两端允许加的最大电压为V。
24．现在医学上使用的心肺机的功能之一是用“电动泵”替代心脏，推动血液循环．如图所示，当线圈中的电流从a流向b时，线圈的左端为极，此时活塞将向运动．三、解答题（共51分）25．（6分）（1）如图所示，一束光射向凸透镜经折射后射到一个平面镜上．请在图中画出射向凸透镜的入射光线和经平面镜反射后的反射光线，并标出反射角的度数。
（2）如图所示为古代护城河上安装的吊桥，其质量分布均匀，请在图中作出吊桥所受重力的示意图和绳拉力F的力臂。
（3）如图所示的插座和电灯（带开关）是组成家庭电路的常用器件，请你用笔画线代替导线将器件分别正确连入电路中26．（8分）压路机是一种利用碾轮的碾压作用，使土壤、路基垫层和路面铺砌层压实的工程机械，广泛用于筑路、筑堤和筑坝等工程。
某型号压路机质量为3×104千克，发动机的额定功率为120千瓦，g 取10牛/千克。
求：（1）如图所示该压路机在沥青路面辗压时，压路机对水平路面的压强为2×105帕，压路机对水平路面的压力为多少牛？压路机与路面的接触面积为多少米2？（1分+2分）（2）该压路机发动机正常工作，压路机在沥青路面上行驶500秒，发动机所做的功为多少焦？（2分）（3）该压路机发动机正常工作，压路机在水平地面以4米/秒的速度匀速直线行驶，则压路机的牵引力为多少牛？压路机受到的阻力为多少牛？（2分+1分）27． （6分）现在电动自行车、电动汽车逐渐普及，它们都采用电动机来获得动力。
某直流电动机的铭牌上标有“220V5.5kW ”，电动机线圈的电阻为0.4Ω。
（1）电动机的工作原理是什么？（1分）（2）该电动机正常工作1h ，消耗多少电能？电动机线圈产生多少热量？（2分+2分）（3）在工作过程中，电动机因故障卡住无法转动，很快就闻到焦糊味道，请你从能量转化角度解释这个现象。
（1分）28． （4分）某同学利用两支同样的蜡烛等实验器材探究平面镜成像的特点。
（1）实验时，在桌面上铺一张大纸，纸上竖立一块 ，作为平面镜。
在纸上记下平面镜的位置，把一支点燃的蜡烛放在镜前，可以看到它在镜后的像。
再拿一支 的蜡烛，竖立着在镜后移动，直到看上去它跟前面那支蜡烛的像 ____ 。
（2）他在白纸上记下了两支蜡烛的位置，如图所示，A 、B 分别表示两支蜡烛，请画出该同学在S 处看到蜡烛在平面镜中所成像的光路图（保留作图痕迹）30． （3分）在“探究二力平衡的条件”实验中，小明选择了如图的装置，把小卡片两端细线绕过滑轮，并挂上钩码（1） 实验中选择小卡片的目的是_______（填“考虑”、“不考虑”） 小卡片的重力；探究两个力大小关系时，应该观察细线两端所挂钩码的个数。
（2）为了探究两个平衡力是否在同一条直线上，进行如下操作： （填“挤压”、“翻转”或“旋转”）小卡片，松手后 观察小卡片是否平衡．（3）小明利用弹簧测力计代替图中的钩码进行了探究，发现两个力的大小还有较小的差距．你认为形成差距的原因是_____________________（答出一条即可）．29． （6分）在课外实践活动中，小明探究纸锥竖直下落的运动情况．（1）为了测定纸锥下落的快慢，小明用频闪相机拍下某一纸锥下落过程的照片，如图甲所示．再用刻度尺测量照片上AC 之间的距离是 cm ．由照片可知，纸锥下落到B 位置时受到的空气阻力 （选填“大于”、“小于”或“等于”）纸锥下落到C 位置时受到的空气阻力．已知照相机每隔0.2s 曝光一次，照片的缩放比例为1:30，则纸锥经过B 位置时的实际速度为 m/s ．（2）实验中，小明还发现不同纸锥由静止释放下落相同高度所经历的时间不同．通过观察分析，他猜想这可能与纸锥的锥角、锥边的长度、纸锥的质量以及纸面粗糙程度有关．于是他利用同一规格的纸张按相同的方法制作纸锥：先裁剪出一个圆， 再剪下一个缺口，最后用胶水将缺口两边粘合住，制作了a 、b 、c 三个不同的纸锥，如图乙所示．其中锥边r 1>r 2=r 3，锥角α1=α2>α3．①为了研究纸锥从同一高度由静止释放下落到地面的时间与纸锥锥边长度的关系，小明应选择纸锥 （选填“a ”、“b ”、“c ”）来进行对比实验．②在研究纸锥下落的时间与纸锥锥角的关系时，小明将a 、c 两个纸锥分别从同一高度由静止释放下落到地面，用秒表分别测出两纸锥下落的时间，再进行比较总结，得出结论．请你评估小明的实验方案并在现有器材的基础上提出相应的改进方法．评估意见： ．改进方法： ．31． （4分）小凡同学在“探究定滑轮和动滑轮特点”的实验中，装置图如下图所示．（1）在探究定滑轮时，照图乙操作，觉得读数不方便，于是把测力计倒过来，即测力计吊环系在拉绳上，用手拉挂钩，测力计的示数会___________ （“变大”、“变小”或“不变”），其理由是 ______________________________。