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篇一:广州市海珠区2017届第一学期高三调研测试(一)
广州市海珠区2017届第一学期高三调研测试(一) 英 语 注意事项:
1. 本试卷分第I 卷(选择题)和第II 卷(非选择题)两部分。第I 卷1 页至8 页,第II 卷9 页至10 页。
2. 答题前,考生务必将自己的姓名、准考证号填写在答题卡相应的位置。
3.全部答案在答题卡上完成,答在本试卷上无效。
4.考试结束后,将答题卡交回。
第I 卷
第一部分阅读理解(共两节,满分40 分)
第一节(共15 小题;每小题2 分,满分30 分)
阅读下列短文,从每题所给的四个选项(A、B、C 和D)中,选出最佳选项,并在答题卡上将该项涂黑。
A
Do you like shopping? Or does the thought of wandering around the shops fill you with terror?For some of us, shopping is an enjoyable way of spending our spare time and our money. For me, it’s something I would rather avoid. Thank goodness for the Internet! It’s more convenient to buy CDs, electrical items, even food from the comfort of your sofa. But that’s not the only reason: price is an important factor. We can buy goods and services cheaper online. But sometimes the problem is knowing what to buy. This has led to a type of shopping called “showrooming”.
Showrooming is something I’ve done. I will go to a shop to see, touch and try out products but then go home and buy them online at a knock-down price. I’m not alone in doing this. Research by a company called Foolproof, found 24% of people showroomed while Christmas shopping in 2013.
Amy Cashman, head of Technology at TNS UK, says the reasons for this new shopping habit are that “people are lacking time, lacking money and they want security about the products they are buying ”. She explains that consumers are not only shopping online at home but they are using the Internet in store or on their smartphones to shop around.
But does this mean technology will kill shops? Certainly shops will change. They will have to offer more competitive prices or encourage people to buy more by giving in-store discounts or free gifts. We mustn’t forget that buying in a shop means you can get expert advice from the sales assistant and you can get good aftercare. It’s good to speak to a real human rather than look at a faceless computer screen, but at least by showrooming, you get the best of both worlds!
1. The two questions in Paragraph 1 are raised to ________________.
A. introduce the topicB. give two examples
C. compare different opinionsD. get answers from readers
2. According to Amy Cashman, which is not the reason for showrooming?
A. The lack of time.
B. The comfort of the sofa.
C. The shortness of money.
D. The security of the product.
3. The author’s attitude towards showrooming is __________________.
A. critical B. neutral C. casual D. supportive
There is a very instructive incident involving the life of Alexander the Great, King of Greek. Alexander, after conquering many kingdoms, was returning home. On the way, he fell ill and it took him to his death bed. With death staring him in his face, Alexander realized his conquests, his great army, his sharp sword and all his wealth were of no consequence. So, he lay helplessly waiting to breathe his last. He called his generals and said, “I will depart from this world soon, and I have three wishes. Please carry them out without fail.”
“My first desire is that,” said Alexander, “My physicians alone must carry my coffin.” After a pause, he continued, “Secondly, I desire that when my coffin is being carried to the grave, the path leading to the graveyard be spread with gold, silver and precious stones which I have collected.”
The king continued, “My third and last wish is that both my hands should be kept hanging out of my coffin.” Alexander’s favourite general kissed his hand and pressed it to his heart. “Oh, King, we assure you that your wishes will all be fulfilled. But tell us why do you make such strange wishes?”Alexander took a deep breath and said, “I would like the world to know of the three lessons I have just learnt. I want my physicians to carry my coffin because people should realize that no doctor can really cure any bodies. They are powerless and cannot save a person from the people not take life for granted.”
“The second wish of spreading gold, silver and other riches on the way to the graveyard is to tell people that not even a bit of gold will come with me. I spent all my life earning riches but cannot take anything with me. Let people realize that it is just a waste of time to chase wealth.”
“And about my third wish of having my hands hanging out of the coffin, I wish people to know that I came empty-handed into this world and empty-handed out of this world.” With these words, the King closed his eyes. Soon he let death conquer him and breathed his last.
4. The first paragraph suggests that Alexander ________________.
A. wanted to leave the world as he came empty-handed
B. realized that what he got in his life was nothing to him at all
C. was spending a lot time conquering many kingdoms and had earned a great amount of wealth
D. regarded his conquests, his great army, his sharp sword and all his wealth as the most important things
5. The underlined word “clutches” in Paragraph 4 means “___________”.
A. sentence B. attention C. control D. shadow
6. The author intends to ________________.
A. tell us the story of Alexander
B. stress the power of Alexander the Great
C. persuade people to realized what Alexander said
D. introduce readers to the instructive lessons of Alexander
7. What would be the best title of the passage?
A. The Death of Alexander
B. The Greed of Alexander
C. Three wishes of Alexander
D. The Life of Alexander
A new study shows students who write notes by hand during lectures perform better on exams than those who use laptops.
Students are increasingly using laptops for note-taking because of speed and legibility (清晰度). But the research has found laptop users are less able to remember and apply the concepts they have been taught.
Researchers performed experiments that aimed to find out whether using a laptop increased the tendency to make notes “mindlessly” by taking down word for word which the professors said.
In the first experiment, students were given either a laptop or pen and paper. They listened to the same lectures and were told to use their usual note-taking skills. Thirty minutes after the talk, they were examined on their ability to remember facts and on how well they understood concepts.
The researchers found that laptop users took twice as many notes as those who wrote by hand. However, the typists performed worse at remembering and applying the concepts. Both groups scored similarly when it came to memorizing facts.
The researchers’ report said, “While more notes are beneficial, if the notes are taken mindlessly, as is more likely the case on a laptop, the benefit disappears.”
In another experiment aimed at testing long-term memory, students took notes as before but were tested a week after the lecture. This time, the students who wrote notes by hand performed significantly better on the exam.
These two experiments suggest that handwritten notes are not only better for immediate learning and understanding, but that they also lead to superior revision in the future. 8. More and more students favor laptops for note-taking because they can ____________.
A. write more notes
B. digest concepts better C. get higher scores D. understand lecture better
9. While taking notes, laptop users tend to be ________________.
A. skillful B. tireless C. thoughtful D. mindless 10. The author of the passage aims to _________________.
A. examine the importance of long-term memory
B. stress the benefit of taking notes by hand
C. explain the process of taking notes
D. promote the use of laptops
11. The passage is likely to appear in _________________.
A. a finance report
B. a computer textbook
C. a science magazine
D. a newspaper advertisement
If you don’t think technology can improve your trip, meet Judy Williams. When she and her husband recently checked into Blu Hotel in Zurich, a clerk asked them to sign the dotted line on a room rate hundreds of dollars higher than their online offer.
“It was not a cheap stay,” says Williams, a lawyer from Billings, Mont. But it became more of one after her husband fired up the Booking.com app he’d used to book their room on his smartphone. “As soon as we showed him the cost, he honored it,” Williams says.
Technology may create challenges for travelers but it can also solve them. It’s more than making sure of a hotel cost. The latest Booking.com can help users select hotels by location, make a secure booking and view the confirmed (已确认的) cost so they never need to re-discuss their hotel price.
Another pain point for travelers is traffic that eats away precious vacation time. There’s a new app called Commute which is aimed at users who have to make the same trip every day. But if you’re headed to Los Angeles or Honolulu, where visitors can easily get stuck in hours of heavy traffic, Commute can help.
Just input basic information about your destination and expected leaving time, and the app will start sending you traffic information 15 minutes before you leave. Testing Commute proved to be a challenge for me, because my home address is about 900 miles from my place of work. But if you have only a short distance to travel through a heavily populated area, you can use Commute to avoid traffic jams.
Another source of travel-related problems is money. That’s particularly true when you’re dealing with a foreign currency. The latest Travel Money Tracker helps travelers prevent currency mix-ups. It immediately changes a country’s native currency to yours, so you know exactly how much that Espresso (浓咖啡) in Milan costs in dollars. It can also warn you when you’re overspending, which can sometimes be a problem when you’re on vacation. The only catch, of course, is that you have to remember to record all your purchases.
Taken together, these apps solve some of the most common travel problems. But not all of them. Some things, no smartphone can fix, which means I get to keep my job – for now at least.
12. What does the writer want to tell through the example of Judy Williams? A. The cost of Blu Hotel was higher than that of others. B. The clerk was very friendly and patient.
C. The smartphones have many functions.
D. Technology can make our trips better.
13. Commute is not suitable for those who_______________. A. have a long journey
B. go on the same trip every day C. can easily get stuck in traffic jams
D. travel a short distance downtown
14. What is the function of Travel Money Tracker?
A. It tells people how much Espresso costs.
B. It warns people when they are shopping.
C. It changes the native currency to yours.
D. It records all people’s purchases.
15. What is the purpose of this passage?
A. To encourage people to travel.
C. To help people with technology problems.
D. To provide people with traveling information.
第二节(共5 小题;每小题2 分,满分10 分) 根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。 Is bottled water better for you than tap? Or should you choose vitamin-eiched water? Experts say, skip it all. None of these products is likely to make you any healthier. Below, we look at four major
If you are not thirsty, your fluid intake is likely “just right”.
Myth No. 1: Drink eight glasses each day.
really knows,” says Dr. Stanley Goldfarb, a kidney expert at the University of Pennsylvania.Myth No. 2: Lots of water equals healthier skin.
a limited effect. “It’s such a tiny part of what’s in the body,” says Goldfarb. “It’s very unlikely that one’s getting any benefit.” A more accurate statement may be: drinking water is a helpful tool for dieters. “Water is a great strategy for dieters because it has no calories,” says Madeline Fernstrom of the University of Pittsburgh. “So you can keep your mouth busy without food and get a sense of satisfaction.” But water is not magical, she adds, “Other zero-calorie options such as diet sodas are fine, too.”
Myth No. 4: It’s easy to get dehydrated (脱水的)during a workout.
also obvious that individuals in hot, dry climates have an increased need for water,” says Goldfarb. “But for a walk in the park, no water bottle is necessary.”
A. So where does the standard advice come from?
B. But it’s unclear whether these changes are clinically significant.
C. So for a 200-pound man, this means losing 4 pounds of water.
D. Drinking extra water leads to weight loss.
E. Drink as much water as you can.
F. So, if you take a 200-pound man, he’s 120 pounds of water.
G. But first, how do you know if you’re drinking enough water?
篇二:广州市海珠区2017届高三上学期调研测试(一)(文数)
广州市海珠区2017届高三上学期调研测试(一)
数学(文科)
注意事项:
1.本试卷分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分.答卷前,考生务必将自己的姓名、准考证号填写在答题卡上.
2.回答第Ⅰ卷时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号涂黑.如需改动,用橡皮擦干净后,再选涂其它答案标号.写在本试卷上无效.
3.回答第Ⅱ卷时,将答案写在答题卡上,写在本试卷上无效. 4.考试结束后,将答题卡一并交回.
第Ⅰ卷
一、选择题:本大题共12小题,每小题5分,在每个小题给出的四个选项中,只有一项是
符合题目要求的.
2
(1)已知集合M???2,0,2,4,?,N?xx?9,则M?N?
??
(A)?0,2? (B)??2,0,2? (C) ?0,2,4? (D)??2,2?
?1?
(2
)复数???(其中i为虚数单位)的值是
22??
(A)?i (B) i (C) ?1 (D)1 (3)要得到函数y?sin?2x?
(A)向左平移(C)向左平移
3
?
?
??
?的图象,只需要将函数y?sin2x的图象 6?
?12
个单位 (B)向右平移
?12
个单位
??
个单位 (D)向右平移个单位 66
m
= n
(4)已知甲、乙两组数据如图茎叶图所示,若它们的中位数相同,平均数
也相同,则图中的m,n的比值 (A)
312
(B) (C) (D)1 839
(5)如图,在底面边长为1,高为2的正四棱柱ABCD?A1B1C1D1中,
点P是平面A1B1C1D1内一点,则三棱锥P?BCD的正视图与侧视
图的面积之和为
(A)2(B)3(C)4(D)5
x2y2
(6)设点P是双曲线2?2?1(a?0,b?0)上的一点,
ab
F1,F2分别为双曲线的左、右焦点,已知PF1?PF2,且
PF1?2PF2,则双曲线的离心率为
(A
(B
(C)2(D
?y?x?
(7)在平面直角坐标系中,已知点A?2,?1?和坐标满足?x?y?1的动点M?x,y?,
则目
?y??1?
?????????
标函数z?OA?OM的最大值为
(A)4 (B)5(C)6 (D)7 (8)已知函数f?x??x?lnx,则f?x?的图像大致为
(9)若c?1,0?b?a?1,则
(A)ac?bc (B)bac?abc(C)alogbc?blogac(D)logac?logbc
(10)在△ABC中,角A,B,C的对边分别是a,b,
c,已知b?c,a2?2b2(1?sinA),则A?
3ππ
(B)
43 ππ
(C)(D)
4 6
(A)
(11)执行如图所示的程序框图,则输出的结果为 (A)?1 (B)1(C)?2 (D)2
(12)设奇函数f?x?在??1,1?上是增函数,且f??1???1,
若函数f?x??t?2at?1对所有的x???1,1?都成立,
2
当a???1,1?时,则t的取值范围是
11
?t? (B)?2?t?2 2211
t?或t??或t?0 (D)t?2或t??2或t?0 (C)
22
(A)?
第Ⅱ卷
本卷包括必考题和选考题两个部分.第(13)题~第(21)题为必考题,每个试题考
生都必须作答.第(22)题~第(24)题为选考题,考生根据要求作答. 二、填空题:本大题共4小题,每小题5分.
????
(13)设向量a??x?1,2?,b??1,x?,且a?b,则x? .
(14)已知???
π?3π????3??
,2??,且cos?????,则tan?????.
4?54????2?
x2y2
(15)已知椭圆2?2?1?a?b?0?的左、右焦点分别为F1,F2,上、下顶点分别是
ab
??????????
B1,B2,点C是B1F2的中点,若B1F1?B1F2?2,且CF1?B1F2,则椭圆的方程
三、解答题: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)
在公差不为零的等差数列?an?中,a1?2,且a1,a2,a4成等比数列. (Ⅰ)求数列?an?的通项公式;(Ⅱ)令bn?
1
(n?N*),求数列?bn?的前n项和Tn.
an?an?1
(18)(本小题满分12分)
如图,在四棱锥P?ABCD中,底面ABCD是菱形,?DAB?60?,PD?平面ABCD,PD?AD?1,点E,F分别为AB和PD的中点.
(Ⅰ)求证:直线AF//平面PEC;
(Ⅱ)求三棱锥P?BEF的体积.
D
A
(19)(本小题满分12分)
第18题图
某商店计划每天购进某商品若干件,商店每销售一件该商品可获利润60元,若供大于求,剩余商品全部退回,但每件商品亏损10元;若供不应求,则从外部调剂,此时每件调剂商品可获利40元. (Ⅰ)若商店一天购进该商品10件,求当天的利润y(单位:元)关于当天需求量n(单位:件,n?N)的函数解析式;
(Ⅱ)商店记录了50天该商品的日需求量n(单位:件,n?N),整理得下表:
若商店一天购进10件该商品,以50天记录的各需求量的频率作为各需求量发生的概率,求当天的利润在区间?500,650?内的概率.
(20)(本小题满分12分)
已知点F为抛物线E:y?2px(p?0)的焦点,点A(2,m)在抛物线E上,且到原点的距离为
(Ⅰ)求抛物线E的方程;
(Ⅱ)已知点G(?1,0),延长AF交抛物线E于点B,证明:以点F为圆心且与直
线GA相切的圆,必与直线GB相切.
(
21)(本小题满分12分) 已知函数f?x??xlnx?
(Ⅰ)求a的取值范围;
2
a2
x?x?a(a 2
(Ⅱ)设两个极值点分别为x1,x2,证明:x1?x2?e2.
请考生从第(22)、(23)、(24)三题中任选一题作答.注意:只能做所选定的题目.如果多做,则按所做的第一个题目计分.作答时请用2B铅笔在答题卡上将所选题号后的方框涂黑. (22)(本小题满分10分)选修4—1:几何证明选讲
如图,在?ABC中,CD是?ACB的平分线,?ACD的外接圆交BC于点E, AB?2AC.
(Ⅰ)求证:BE?2AD;
(Ⅱ)当AC?1,EC?2时,求AD的长.
(23)(本小题满分10分)选修4—4:坐标系与参数方程
已知在直角坐标系xoy中,曲线C的参数方程为?
坐标系(与直角坐标系xoy取相同的长度单位,且以原点O为极点,以x轴正半轴为极轴)中,直线l
的方程为?sin???(Ⅰ)求曲线C在极坐标系中的方程;
(Ⅱ)求直线l被曲线C截得的弦长.
(24)(本小题满分10分)选修4—5:不等式选讲
已知函数f(x)?2x??x?2. (Ⅰ)解不等式f(x)?0;
(Ⅱ)若存在实数x,使得f(x)?x?a,求实数a的取值范围.
?x?2?2cos?,
??为参数?,在极
y?2sin?,?
?
?
??
??. 4?
数学(文科)参考答案
评分说明:
1.本解答给出了一种或几种解法供参考,如果考生的解法与本解答不同,可根据试题的主要考查内容比照评分参考制订相应的评分细则.
2.对计算题,当考生的解答在某一步出现错误时,如果后继部分的解答未改变该题的内容和难度,可视影响的程度决定后继部分的给分,但不得超过该部分正确解答应得分数的一半;如果后继部分的解答有较严重的错误,就不再给分.
3.解答右端所注分数,表示考生正确做到这一步应得的累加分数. 4.只给整数分数.选择题不给中间分. 一.选择题:本大题共12小题,每小题5分.
(1)B (7)B
(2)C
(3)A
(4)A
(5)A
(6)D
(8)A (9)D (10)C
(11)D (12)D
二.填空题: 本大题共4小题,每小题5分.
13x2y2
??1 (16)7? (13) (14) (15)
3443
三.解答题
(17)(本小题满分12分)
解:解: (Ⅰ)设数列?an?的公差为
d?d?0?,…………1分
由题意知?a1?d??a1?a1?3d?, …………2分 即?2+d??2?2?3d?,即d?d?2??0,又d?0,所以d?2.…………3分 故数列?an?的通项公式an?2??n?1??2?2n. …………5分
(Ⅱ)由(Ⅰ)得bn?
2
2
111111
……7分 =???)
an?an?12n?2n?14nn?14nn?1
所以Tn=b1?b2?b3???bn …………8分
1??1??11??11?1???1=??1?????????????????…………9分 4??2??23??34?nn?1???
1?1?=?1?? …………10分 4?n?1?
=
n
.…………11分
4n?1n
.…………12分
4n?1所以数列?bn?的前n项和Tn=(18)(本小题满分12分)
篇三:广州市荔湾区2017届高三调研测试(二)(物理)
广州市荔湾区2017届高三调研测试(二)
物 理 第Ⅰ卷
二、选择题:本题共8小题,每小题6分。在每小题给出的四个选项中,第14~17题只有一项符合题目要求,第18~21题有多项符合题目要求。全部选对的得6分,选对但不全的得3分,有选错的得0分。
14.t=0时,甲乙两汽车从相距60 km的两地开始相向行驶,它们的v-t图象如图所示。
忽略汽车掉头所需时间,下列对汽车运动状况的描述正确的是 A.在第1小时末,乙车改变运动方向B.在第2小时末,甲乙两车相遇
C.在前4小时内,甲车运动加速度的大小总比乙车的大D.在第4小时末,甲乙两车相距20 km
15.在粗糙水平地面上与墙平行放着一个截面为半圆的柱状物体A,A与竖直墙之间放另一
截面也为半圆的柱状物体B,整个装置处于静止状态,截面如图所示。设墙对B的作用力为F1,B对A的作用力为F2,地面对A的作用力为F3。在B上加一物体C,整个装置仍保持静止,则 A.F1保持不变,F3增大 B.F1增大,F3保持不变 C.F2增大,F3增大 D.F2增大,F
3保持不变
16.如图所示,一小球由不可伸长的轻绳系于一竖直细杆的A点,当竖直杆以角速度ω匀
速转动时,小球在水平面内做匀速圆周运动。关于小球到A点的竖直距离h与角速度ω的关系图线,正确的是
17.某人在地面上用体重秤称得体重为
G,之后他将体重秤移至电梯内称其体重,电梯运行
的v-t图线如图所示(取电梯向上运动的方向为正)。设t0至t1时间段内体重秤的示数为F1,t1至t2时间段内体重秤的示数为F2,t2至t3时间段内体重秤的示数为F3,下列说法正确的是
A.F1=F2=F3=G B.F1>F2>F3>GC.F1<F2=G<F3D.F1=F3<F2=G 18.如图,轰炸机沿水平方向匀速飞行,到达山坡底端正上方时释放一颗炸弹,并垂直击中
山坡上的目标A。已知A点高度为h,山坡倾角为θ,由此可算出 A.轰炸机的飞行高度 B.轰炸机的飞行速度 C.炸弹的飞行时间 D.炸弹投出时的动能
19.“嫦娥一号”和“嫦娥二号”卫星相继完成了对月球的环月飞行,标志着我国探月工程的第
一阶段已经完成。设“嫦娥二号”卫星环绕月球的运动为匀速圆周运动,它绕月球运行的周期为T,已知月球的质量为M、半径为R,引力常量为G,则卫星
2?R
T2?
B.绕月球运动的角速度??
T
A.绕月球运动的线速度v?
4?2R
C.绕月球运动的向心加速度a? 2
T
D.
距月球表面的高度为h?R 20.如图甲所示,一轻质弹簧的下端固定在水平面上,上端放置一物体(物体与弹簧不连接),
初始时物体处于静止状态。现用竖直向上的拉力F作用在物体上,使物体开始向上做匀加速运动,拉力F与物体位移x之间的关系如图乙所示(g=10m/s2),则下列结论正确的是
A.物体的质量为2kg B.弹簧的劲度系数为7.5N/cm C.物体的加速度大小为5m/s2
D.物体与弹簧分离时,弹簧处于压缩状态
甲
乙
21.如图所示,倾角为α的固定斜面下端固定一挡板,一劲度系数为k的轻弹簧下端固定在
挡板上。现将一质量为m的小物块从斜面上离弹簧上端距离为s处,由静止释放,已知物块与斜面间的动摩擦因数为μ,物块下滑过程中的最大动能为Ekm,则小物块从释放到运动至最低点的过程中,下列说法中正确的是 A.μ<tanα
B.物块刚与弹簧接触的瞬间达到最大动能
C.弹簧的最大弹性势能等于整个过程中重力与摩擦力对物块做功之和
D.若将物块从离弹簧上端2s的斜面处由静止释放,则下滑过程中物块的最大动能小于2Ekm
第Ⅱ卷
22.(5分)某学生用如图甲所示的装置研究小车的匀变速直线运动,打点计时器接到频率为50 Hz的交流电源上。如图乙所示为实验时得到的一条纸带的一部分,0、1、2、3、4、5、6为计数点,相邻两计数点间还有4个打点未画出。从纸带上测出x1=3.20 cm,x2=4.52 cm,x5=8.42 cm,x6=9.70 cm。则打点计时器在打计数点5时小车的瞬时速度大小v5 = ________m/s,小车运动的加速度大小a =________m/s2 (两空均保留两位有效数字)。若实验时电源的电压升高了,测得的加速度________ (填“大于”“等于”或“小于”)实际的加速度。
23.(10分)用如图a所示装置做“验证动能定理”的实验。实验时,通过电磁铁控制小铁球从P处自由下落,小铁球依次通过两个光电门甲、乙,测得遮光时间分别为Δt1和Δt2,两光电门中心点间的高度差为h。
(1)用游标卡尺测得小铁球直径的示数如图b所示,则小铁球的直径d =__________mm; (2)为验证动能定理,还需知道的物理量是__________________________(填物理量名称及符号),验证动能定理的表达式为:__________________________________________; (3)由于光电门甲出现故障,某同学实验时只改变光电门乙的高度,进行多次实验获得多组数据,分别计算出各次小铁球通过光电门乙时的速度v,并作出v2-h图像。图(c)中给出了a、b、c三条直线,他作出的图像应该是直线_________;由图像得出,小铁球初始位置P到光电门甲中心点的高度差为_________cm,铁球通过光电门甲时的速度为_________m/s2(两空均保留两位有效数字)。
24.(14分)广州中山大道、广州大道等路段设置了“绿波带”,根据车辆运行情况对各路口红
绿灯进行协调,使车辆通过时能连续获得一路绿灯。设一路上某直线路段每间隔L=500 m就有一个红绿灯路口,绿灯时间△t1=50 s,红灯时间△t2=40 s,而且下一路口红绿灯亮起总比当前路口红绿灯滞后△t=50s。要求汽车在下一路口绿灯再次亮起后能通过该路口,汽车可看做质点,不计通过路口的时间,道路通行顺畅。
(1)若某路口绿灯刚亮起时,某汽车恰好通过,要使该汽车保持匀速行驶,在后面道路
上再连续通过3个路口,汽车匀速行驶的最大速度是多少?最小速度又是多少?(计算结果保留两位有效数字)
(2)若某路口遭遇红灯,待绿灯刚亮起时,某汽车由静止开始,以加速度a=2 m/s2匀加
速运动,加速到第(1)问中汽车匀速行驶的最大速度以后,便以此速度一直匀速运动。试通过计算判断,当该汽车到达下一个路口时能否遇到绿灯。
25.(18分)一长木板在水平地面上运动,从木板经过A点时开始计时,在t=1.0s时将一相
对于地面静止的小物块轻放到木板上,此后木板运动的v-t图线如图所示。己知木板质量为物块质量的2倍,物块与木板间及木板与地面间均有摩擦,物块与木板间的最大静摩擦力等于滑动摩擦力,且物块始终在木板上,取重力加速度的大小g=10m/s2,求:
(1)物块与木板间的动摩擦因数μ1及木板与地面间的动摩擦因数
μ2;
(2)木板离A点的最终距离; (3)木板的最小长度。
35.【物理—选修3-5】(15分)
如图,水平轨道A点左侧光滑,右侧粗糙,距A点s=1.0m的B端与半径R=0.25m的光滑半圆轨道BCD相切,半圆的直径BD竖直。一小物块b以v0=3.0m/s的速度,与静置于A点的小物块a发生弹性碰撞。碰后a沿水平轨道运动,然后滑上轨道BCD。已知小物块a的质量ma=1.0kg,a与AB轨道间的动摩擦因数μ=0.20,g取10m/s2。
(1)若a到达半圆轨道的中点C点时速率vC=1.0m/s,求a进入半圆轨道的B点时对轨道
的压力大小;
(2)若a能滑上圆轨道,且仍能沿圆轨道滑下,求a碰后的最大速度; (2)若a能滑上圆轨道,且仍能沿圆轨道滑下,求b的质量mb的取值范围。
s
《2017广州高三调研(2017广州零模)》出自:百味书屋
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