篇一：北仑中学2007年保送生资格认定英语试卷
2007年北仑中学保送生资格测试
英语试卷
I：单项填空（共20小题；每小题１分，满分20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. Rather than ____on a crowded bus, he always prefers___ a bicycle. A. ride; rideB. riding; rideC. ride; to rideD. to ride; riding
2. Shanghai is the first city in our country to build a ______ Maglev train, from the downtown to the airport.
A. highly-speed B. high-speed C. high-speeded D. fast-speeded 3. Fish easily ______ in summer. You’d better put it into the refrigerator.A. went bad B. go badly C. goes badly D. goes bad 4. ---What would you like for ______ breakfast, Mr. Black?
--- Three pieces of bread with ______ cup of black tea, please.A. a; a B. /; the C. the; a D. /; a
5. --- Did you and your classmates ride your bicycles to the beach last Sunday?--- Yeah, ______ we had!
A. how a fun B. what fun C. what a fun D. how fun 6. --- Everyone will make a mistake.
--- Yeah, but we should correct it ______ it gets worse. A. whenB. beforeC. afterD. until 7. --- Excuse me, is this seat taken?
--- _______. That man left some books here and he has gone to the dining room for his lunch.
A. I'm afraid soB. I don't think so C. I don't knowD. I hope not 8. --- I was watching TV when the fire broke out last night. What about you, Bill? --- I _______ computer games. A. playedB. have playedC. had playD. was playing 9. Is this book ______ you borrowed from the library?A. that B. which C. the one D. it
10. Mary, here; everybody else, stay where you are. A.come B.comes C.to comeD.coming 11. --- Are you coming to Jim’s birthday party?
--- I’m not sure. I ______ go to the concert instead.A. should B. would C. must D. might 12. --- Excuse me, could you tell me ______?
--- Sorry, I’m new here, too.
A. where is the nearest bank B. how can I get to the bank
C. which is the way to the bank D. is there a bank near here
13. --- What do you think of the TV sets here?
--- The price of the TV sets in your shop is ______ than that in other shops, but the quality is not as ______
A. cheaper; wellB. lower; good C. more expensive; brighterD. higher; dearer 14. I won’t let you in ______ you show me your pass.A. if B. when C. because D. unless 15. --- Why won’t Mr. Wu go to Dalian with us? --- Because he ______ to Hongkong on business.
A. had been B. has been C. has gone D. had gone 16. --- Mum, we’re going to visit an island this wekend.
--- ______!
A. Goodbye B. That’s OK C. Not at all D. Have a good trip. 17. --- Do you like the new coat, Jack? --- Well, let me ______ and see.
A. wear it on B. put on it C. try it on D. dress on it 18. The number of people ______ lost homes ______increasing.
A. have; are B. who have; are C. who has; is D. who have; is 19. --- ______ will the next bus come?
--- In about ten minutes.
A. How far B. How soon C. How long D. How often 20．--- Could I call you by the first name？
--- Yes, you _____.
A. will B. could C. may D. must
II：完形填空（共20小题；每小题１分，满分20分）
阅读下面短文，掌握其大意，然后从各题所给的四个选项（A、B、C和D）中，选出最佳选项。
Many years ago there lived a young couple in a small town. The husband was out of job for a long time and the wife make a living by sewing（缝纫）for others. They were so poor that there was almost nothing in the house but a jar（坛、罐）under a table, in 23 was a little rice 24 from their neighbor for the coming New Year. 25 New Year’s Eve, the wife had already fallen asleep, but the husband was in bed, worrying about the life. Suddenly he heard something. In the darkness he saw a man breaking into the room.
“It be a thief.” He thought, “but it doesn’t matter, there is nothing that can be .” So he to be asleep and kept watching over the thief.
The thief began to 30 the room. At last he found the rice in the jar.
“But 31 can I take it away?” the thief thought hard. Then he had an idea. He took off his coat and it on the ground between the bed and the table. After that he turned round to take the jar.
Now the husband realized what the thief 33 . He 34the coat quickly and covered himself with it the thief was turning around.
The thief the jar, poured the rice out on the place where he had just spread his coat and squatted (蹲) down to feel it. But his surprise, his coat had disappeared . “Hey”, he couldn’t help out. The woke up the wife. She asked her husband, “Did you hear any sound? Maybe there is a thief in the room.”
“ Nonsense(胡说)!” replied her husband. “Go back to sleep. There is no thief in the room.”
“No, that’s 40 ,” the thief shouted loudly. “If there isn’t a thief, then, where’s my coat?”
21. A. was able to 22. A. good23. A. it
24. A. borrowed 25. A. During 26. A. working 27. A. will 28. A. lost 29. A. pretended 30. A. look into 31. A. what 32. A. used
B. wanted to B. old B. which B. asked B. At
B. sewing B. must B. carried B. tried B. search B. when B. hung B. did
B. hold up B. before B. laid B. in
C. had to C. nice C. where C. lent C. In
D. would D. broken D. that D. taken D. On D. thinking D. may D. stolen D. started D. look up D. how D. forgot D. could do D. picked up D. as soon as
C. lying C. can
C. destroyed C. decided C.search for C. why C. spread
33. A. had done 34. A. gave up 35. A. while 36. A. shook 37. A. with 38. A. to cry 39. A. words 40. A. right
C. would do C. brought up C. until
C. liftedD. touched C. for D. to C. to jump C. noise C. nothing
D. jumping
D. saying
D. impossible
B. crying B. voice B. all right
III：阅读理解（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A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
(A)
Eye doctors in Shanghai found out recently that the nearsightedness（近视） among
primary and middle school students has something to do with the color of the paper in their textbooks and notebooks.
The doctors suggested that yellow paper should be used to replace（代替） the white ones.
According to their research the experts found out white paper reflects（反射） too much light and easily tires a person’s eyes. Yellow paper, however, doesn’t look so sharp to a person’s eyes. In other words, it is much milder（温和的） to the eyes of students who may do reading or writing for hours.
The experts’ research finding was based on first-hand information and a number of scientific experiments including a recent study among the students from forty-one middle schools. To make the students understand the truth, Shanghai Education Department Co. Ltd has produced textbooks and exercise-books made of yellow paper. The books will be used in the whole city soon.
41. The passage mainly wants to tell us _______.
A. m
B. many students are nearsighted in middle schools C. yellow paper is less harmful to students’ eyes
D. Shanghai Education Department Co. Ltd has produced textbooks and exercise-books made of yellow paper
42. The doctors suggested that yellow paper should be used to replace the white one because ________.
A. yellow paper makes one’s eyes easily tired
B. yellow paper reflects too much light
C. there isn’t enough white paper
D. the white paper is not as mild as the yellow one to a person’s eyes
43. “ The experts’ research finding was based on first-hand information” means that ________.
A. the experts have done a lot of experiments about it
B. the students from 41 middle schools told them about it C. the experts got the result with their own hands
D. the experts found out the result according to their own experience 44. ________ will use books made of yellow paper.
A. 41 middle schools B. The whole city of Shanghai C. ChinaD. The whole world 45. The students easily become nearsighted because ________.
A. their books are made of yellow paper B. their books are made of white paper
C. they use their eyes too long without rest at a time D. they often do reading
( B )
Coad was eighteen months old when he crawled up on a piano bench and began playing some he had heard on the radio. At three he wrote his first piano piece, which he named “Congrajulashons” because, like Mozart, he could compose music before he could spell.
At ten, Coad studied at Juilliard School in New York City, one of the best music schools in the world. He spent five hours a day playing the violin and the piano. “I’m like and unlike other children,” he said. “I’m interested in the same things as other children, such as books and films. And I’m not such a big fan of practising, but I have to do it.”
Early this year Coad won a big competition for young composers（作曲家） . He was the youngest of more than 450 youths who entered.
Coad loves to compose classical music. He has written thousands of pieces of all kinds. When he has time, he reads Harry Potter. He also goes to see Spiderman. 46. The writer mainly wants to tell us ______.
A. about the whole life of Coad B. about a famous young composer C. about a good music school D. how to become a successful composer 47. Cad reads Harry Potter and sees Spiderman because he ______. A. has the same interests as other children B. is unlike other children C. wants to kill time
D. love books and films of all kinds
48. Coad composed his first piano piece ______.
A. when he was ten years old B. before he studied at Juilliard School C. when he met Mozart D. after he learned to spell 49. The Chinese for the underlined word “tunes” should be ______. A. 乐器B. 音响 C. 乐谱 D. 曲调
50. Which of the following about Coad is TRUE?
A. He could play the piano very well when he was one year and a half. B. He won a big competition in New York for young pianists. C. He practised playing the piano as well as the violin at school. D. He has composed thousands of beautiful songs for children.
(C)
There was a time when if a lady got onto a crowded bus or train, a gentleman would stand up at once and offer her his seat. But now, things are different. Today a gentleman will probably look out of the window, or, if he feels a bit shy, hides behind his newspaper. Either way, the lady will have to stand until someone else gets off.
You can't entirely blame（责备） men for this change in manners, though. Gone are the days when women could be treated as weakers without causing any trouble. A whole generation of women has grown up demanding（要求） equality（平等） with men; not
篇二：2006年宁波北仑中学保送生招生数学试题(新人教版)-
2006年北仑中学保送生招生数学试题
一、选择题(有且只有一个正确答案，每小题5分，满分30分)
1．已知直线y=x上有两点A(1，1)，B(3，3)，在y轴上存在一点P，它到点A，B的距离之和最小，则点P的纵坐标是( ) A. 1 B.
35 C. 2 D. 22
2．在四边形ABCD中，对角线A C是BD的垂直平分线，∠ADB=30°，∠CDB=45°，且AB=2 ，则四边形ABCD的面积是( )
A. 9+33 B. l8+63 C. 3+9 D 33 +
9
2 2
3．某学生想把放置在水平桌面上的一块三角板ABC(∠ACB=90°，∠A=30°)，绕点C按顺时针方向旋转θ角，转到△ A'B'C的位置，其中A'、B'分别是A、B的对应点，B在A'B'上(如图所示)，则θ角的度数为( )
A. 30° B.45° C.60° D . 90°
4.规定n!=n×(n-l)×(n-2)×……×3×2×1(例如：4!=4×3×2×1)，那么S=1!+2!+3!+4!+…+2006!的个位数是( ) A . O B.l C.2 D.3 5．某城市有四条直线型主干道分别为l1，l2、l3、l4，l3和l4相互相交．l1和l2相互平行且与l3、l4相交成如图所示的图形，则共可得同旁内角( )对。
A. 4 B.8 C .12 D .16
6．今有一个圆型转盘，先把它的圆周6等分，然后从这6个分点中任取3点构成三角形，则能构成直角三角形的概率为( ) A.
1234B.C. D. 5555
二、填空题(每小题6分，满分30分)
7.不论实数k为何值，直线(2k+1)x+(1-k)y+7-k=0恒经过的定点坐标是 。 8．化简：
6?36?25?3?32?1
=
25?3?1
9．已知直线y=2x+1经过适当平移后的图象与原来的图象重合，试写出能满足要求的一种平移方案 。 10．某人想买A、B、C三件物品，若买l 3件A物品，5件B物品， 9件C物品，则需9．25元；若买2件A物品，4件B物品，3件C物品，则需3．2元。试问若买A物品，B物品，C物品各2件，则需 元。 11．已知实数x，y满足x2+xy+y2=1，则x2-xy+y 2的最大值是 ，最小值是 。
三、解答题(第12题12分，第13、l6题10分，第14、l5题l4分，满分60分
)
12．(本题l 2分)已知抛物线y=x2+(2 a-1)x+a2+3a+
17
与x轴交于点A(x1，0)，B(x2，0)。4
(1)求实数a的取值范围；(2)令S=x12+x22，求S的取值范围。
13．(本题l 0分)若方程x2-37x+37k-l=0至少有一个正整数根，求所有正整数k的和。
14．(本题l 4分) (1)已知?
1131171113??,???,1??2?,……试猜测22222
2612122334
?
11
的结果，并加以证明； ?22
n(n?1)
11111111
????????????, 2222222212233420052006
(2) s=?
求不超过S的最大整数[s]。
15．(本题l 4分)规定三角形的三条内角平分线的交点叫三角形的内心。
(1)已知I为三角形ABC的内心，连结AI交三角形ABC的外接圆于点D，如图所示，连结BD和CD,求证：BD=CD=ID。
(2)己知三角形ABC，AD平分∠BAC且与它的外接圆交于点D，在线段AD上有一点I满足BD=ID 。试问点I是否是三角形ABC的内心?若是加以证明；若不是，说明理由。
16．(本题l 0分)现有质量分别为5克和23克的砝码若干只，在天平上要称出质量为4克的物体，问至少要用多少只这样的砝码才能称出?并证明你的结论。
篇三：北仑中学2007年保送生资格认定科学试卷
北仑中学2007年保送生资格认定考试科学试卷
本卷共31题，总分150分。
可能用到数据：相对原子质量：H-1;C-12;O-16;N-14;S-32;Cu-64;
重力加速度取10m/s2。
一、选择题（每题只有一个正确答案，其中1-10题每题3分，11-20题每题4分，共70分） ．．．．
1．下列变化中与其它三项有本质区别的是
A.食用醋除水垢 B．灯泡钨丝升华 C.双氧水制氧气 D．铁制品生锈
2．下列事实不能说明Zn比Ag活泼的是
A．Zn的熔点为420℃，Ag的熔点为962℃
B．Zn能与稀硫酸反应，Ag则不能
C．自然界没有以单质形式存在的Zn，而有以单质形式存在的Ag
D．Zn能与AgNO3溶液反应，置换出Ag
3．根据你的生活经验判断下列说法错误的是
A．胃酸过多吃生石灰中和 B．用锅盖盖灭油锅中的火焰
C．用木炭除去冰箱中的异味 D．用酒精洗去沾在手上的油漆 A4．化学上用符号“ZX”表示原子的组成，其中X代表元素符号，Z表示原子核内的质子数，
bn?dm-A表示原子核内质子数与中子数之和。已知aX和cY的电子层排布完全相同，则下列
关系正确的是
A．b-a=d-c B．a-m=c+n C．a+n=c-m D．b-n=d+m
5．溶液在我们的生活中的应用特别广泛，下列关于溶液的说法正确的是
A．不饱和溶液都可通过降低温度的方法而使变成饱和溶液
B．同种物质的饱和溶液的质量分数肯定比其不饱和溶液的大
C．蒸发掉原溶液中溶剂的一半可使溶液的溶质质量分数增大一倍
D．CO2通入澄清石灰水变浑浊，得到的溶液中CaCO3已达饱和。
6．自古长江三峡雄奇险秀，滔滔江水奔腾直下．北魏著名地理学家、散文家郦道元在其脍炙人口的《三峡》名篇中写道：“或王命急宣，有时朝发白帝，暮到江陵，其间千二百里，虽乘奔御风，不以疾也．”文中所描写船的平均速度约为
A．5km／h B．50km／h C．100km／h D．10km／h
7．以下所给出的现象中，物体运动状态不发生改变的是 ．．．
A．在弯曲的路上汽车匀速转弯 B．小孩沿笔直的滑梯匀速下滑
C．熟透的苹果从树上下落 D．行驶的火车开始进站
8．蝴蝶飞行时翅膀每秒振动5～6次，蜜蜂飞行时翅膀每秒振动300～400次．假如你的眼睛蒙上，有蝴蝶和蜜蜂分别从你头部附近飞过时，那么
A．能听到蜜蜂飞过，不能听到蝴蝶飞过
B．能听到蝴蝶飞过，不能听到蜜蜂飞过
C．蝴蝶与蜜蜂飞过都能听到，但蝴蝶声音很微弱
D．蝴蝶与蜜蜂飞过都不能听到
9．甲、乙两实心球放入足够深的某种液体中平衡后，所受的浮力之比为F甲：F乙＝2：5。若甲、乙两球的密度之比ρ甲：ρ乙＝1:2，体积之比V甲：V乙＝2:3，则：
A．甲、乙都沉底 B．甲漂浮，乙沉底
C．甲沉底，乙漂浮 D．甲、乙都漂浮在液面上
10．一列以速度v匀速行驶的列车内有一水平桌面，桌面上的A处有一小球．若车厢中的旅
客突然发现小球沿如图（俯视图）中的虚线从A点运动到B点．则
由此可以判断列车的运行情况是
A．减速行驶，向北转弯 B．减速行驶，向南转弯
C．加速行驶，向南转弯 D．加速行驶，向北转弯
11．如图所示，有一建筑工人，他在某次施工中，站在平板AB上，工人通
过拉绳子，可以使自己和板一起匀速上升，且人与平板始终保持接触。
若工人体重为G1，板AB重量为G2，滑轮质量和绳的质量及轴上的摩
擦都可不计，则人对平板的压力为 A.G1?G2
3 B.G2G1?2
33 C.G3G1?2
44 D.G11?G2 4
12．两个等大的水平力F分别作用在物体B、C上．物体A、B、C都处于静止状态．各接触面
与水平地面平行．物体A、C间的摩擦力大小为f1，物体B、C间的摩擦力大小为f2，物体C与地面间的摩擦力大小为f3，则
A．f1?0,f2?0,f3?0B．f1?0,f2?F,f3?0
C．f1?F,f2?0,f3?0D．f1?0,f2?F,f3?F
13．如图所示电路，电源电压不变，闭合开关S，电压表、电流表均有示数，将滑动变阻器的
滑片P向左移动，一会儿发现电压表和电流表示数的比值变．．．．．
小，则电路中可能出现的情况是
A．电阻R1短路，电流表的示数变大
B．电阻R1断路，电压表的示数变大
C．滑动变阻器断路，电压表的示数变小
D．滑动变阻器短路，电压表的示数变小
14．在光学中，折射率是这样定义的，让光线从真空（空气）射入某介质发生折射，如果入射
角是I，折射角是r，则该介质的折射率为n＝sin I / sin r, 当不同颜色的光从真空进入介质时，折射率不同，已知紫光的折射率大于红光，如图所示，相距很近的两束平行的红光．．
和紫光，间距为d，斜射到较厚的玻璃砖的上表面，并从玻璃砖．．
的下表面射出，则下列现象可能出现的是
①两条出射光线仍平行，但距离大于d
②两条出射光线仍平行，但距离小于d
③两条出射光线仍平行，但距离等于d
④两条出射光线不再平行
A．只有② B．只有④ C．只有①② D．只有①②③
15．甲、乙两木块自左向右运动，现用高速摄影机在同一底片上多次曝光，记录下木块每次曝
光时的位置，如图所示，连续两次
曝光的时间间隔是相等的，其中甲
木块的速度跟时间成一次函数关
系，由图可知
A．在时刻t2以及时刻t5两木块速度相同
B．在时刻t3和时刻t4之间某瞬时两木块速度相同
C．在时刻t3两木块速度相同
D．在时刻t4和时刻t5之间某瞬时两木块速度相同
16．一定量的木炭在盛有氮气与氧气混合气体的密闭容器中充分燃烧后，生成CO和CO2，且
测得反应后混合气体中碳元素的质量分数为24%，则其中氮气的质量分数可能为
A．10% B．40% C．60% D．70%
17．已知CaC2与水反应生成C2H2，Mg2C2与水反应生成C2H4，则下列说法正确的是
A．Zn2C2与水反应生成C2H2 B．Al2C3与水反应生成C3H6
C．Mg3C2与水反应生成C2H4 D．Ca4C3与水反应生成C3H4
18．仔细观察下列三个反应：①HCl+NaAc=NaCl+HAc；②HAc+NaHCO3=NaAc+H2CO3；
③H2CO3+NaClO=NaHCO3+HClO；（Ac-为酸根阴离子）。则下面反应方程式错误的是
A．HCl+NaHCO3=NaCl+H2CO3 B．HClO+NaAc=NaClO+HAc
C．HAc+NaClO=NaAc+HClO D．HCl+NaClO=NaCl+HClO
19．现有化学反应mA+nB=pC，已知2gA和5gB充分反应生成了WgC，10gA和8gB充分反
应生成了2WgC，则W的值是
A．4 B．5 C．6 D．7
20．氯酸钾化学式为KClO3，其中氯为+5价；有一种碘和氧的化合物可以称为碘酸碘，其中
碘元素呈＋3、＋5两种价态，则这种化合物的化学式为
A．I2O4 B．I3O5 C．I4O7 D．I4O9
二、填空题
21、（8分）甲烷的结构式为： 乙烷的结构式为：
丙烷的结构式为：
n烷（含n个碳原子）的结构式为：
试回答：
（1）丙烷的化学式为： ；n烷的化学式为： （原子个数以
带“n”式子表示）；
（2）若原子之间的每一根短线表示一个“共价键”，那么丙烷分子有 个“共价键”，
n烷分子有个“共价键”。
22.（10分）已知Cu和稀H2SO4不反应，而Cu和浓H2SO4在加热的条件下可以反应，生成
盐A、气体氧化物B和水。盐A使溶液呈现蓝色，气体氧化物B中含氧的质量分数为50%。
（1）请写出化学式：A，B ；
（2）请写出Cu和浓H2SO4反应的化学方程式： ；
（3）足量的Cu和100g98%的浓H2SO4反应可以生成气体B的质量为Wg，W的取值范
围为。
23．（10分）已知反应：① Cu+4HNO3（浓）=Cu(NO3)2+2NO2↑(红棕色)+2H2O；
② 3Cu+8HNO3（稀）=3Cu(NO3)2+2NO↑(无色)+4H2O；
③ 2NO+O2=2 NO2；
④ 4NO2+O2+2H2O=4HNO3；
一个带有活塞的容器（如右图），活塞可以上下移动但不漏气。容器内有6.4gCu粉、一定量未知浓度的HNO3和足量的空气。反应足够时间后，Cu粉消失。请回答：
（1）描述反应过程中的现象：
①活塞： ；
②空气部分：；
③Cu与溶液： ；
（2）容器内消耗的O2为 g。
24．（12分）有些化学反应如N2+3H2=2NH3在一定条件下可以反应，但28gN2和6gH2并不能
完全转化为34gNH3，因为N2和H2反应生成NH3的同时也有部分NH3分解成N2和H2，这个现象我们称之为“可逆反应”，该反应也可以表示成N2+3H22NH3。一段时间后，单位时间内生成的NH3和分解的NH3相等时，三种成分的质量不再变化，我们称之为“化学平衡”。
现有一个体积固定的密闭真空容器。
ⅰ）若开始充入56gN2和12gH2，一段时间后达到化学平衡，发现容器内有42gN2、9gH2
和17gNH3；
ⅱ）若开始充入68gNH3，一段时间后达到化学平衡，发现容器内也是42gN2、9gH2和
17gNH3；
试回答：
（1）若开始充入28gN2、6gH2和 gNH3，一段时间后达到化学平衡，容器内有42gN2、
9gH2和17gNH3；
（2）若开始充入58g N2和10g H2，一段时间后达到化学平衡，容器内成分 （填“是”
或“不是”）42gN2、9gH2和17gNH3；
（3）若开始充入 g N2、3gH2和 g NH3，一段时间后达到化学平衡，容器也是
42gN2、9gH2和17gNH3；
（4）若开始充入agN2、bgH2和cgNH3，一段时间后达到化学平衡，容器也是42gN2、9gH2
和17gNH3，则a与c、b与c之间应该满足的关系是。
25.（3分）根据通电螺线管中的电流方向，标出螺线管以及两个小磁针的N、S极
26．（6分）两个完全相同的容器中，分别盛有甲、乙两种液体，将完全相同的两个小球分别
放入容器中，当两球静止时，液面相平，球所处的位置如图所示，甲、
乙两种液体对容器底的压强大小分别为P甲、P乙，容器底部对桌面的
压力分别为F1 、F2，试比较P甲、P乙以及F1、F2的大小：
P甲 P乙，F1F2（填大于等于或者小于）
27．（4分）如图所示，高度为L、横截面积为S的物块浮在盛满水的杯内，杯
?0?0的高度恰好为2L．水的密度为，物块的密度为，现用外力将物块按2
入水底，问从物块刚好全部浸没到被按到水底的过程中，外力所做的功至
少应为 。
28．（4分）每个电阻的阻值如图所示，请计算出A、B两点之间的总电阻为
29．（4分）我们把放射性元素减少一半所需要的时间称为半衰期，经过一个半衰期，放射性
元素就减少为原来的一半，现在有如图所示的球形放射源，一边向四周放出β射线一边缓慢地匀速前进，在离放射源距离为2L处有一接收器，此时接收器单位时间内接收到的粒子数为N个。放射源从离接收器距离为2L处运动到离接
收器距离为L时，经过的时间恰好为放射源的一个半衰期，
求此时接收器单位时间内接收到的粒子数为 。
（题中可能用到的公式：球的表面积计算公式S?4?R2）
三、解答题
30．（9分）北仑中学每年都举行艺术周科技周活动，在去年的科技周上，一位同学设计的“风
力测试仪”获得了科技小制作一等奖，“风力测试仪”的原理如图所示．电源电压6V，R0为保护电阻，AB为长20cm、阻值为50?的均匀电阻丝．OP
为质量、电阻均不计的金属细杆，下端连接一个重为2N的
球P．闭合开关S，无风时，OP下垂并与电阻丝的B端接
触；有风时，球P受风力的作用，使金属细杆OP绕悬挂点
O偏转，当偏转到电阻丝的A端时，电流表示数为0.6A．已
知悬挂点O与电阻丝B端的距离为10cm，金属细杆OP始
终与电阻丝AB接触良好且无摩擦，求：
(1)R0的阻值；
(2)无风时电流表示数；
(3)在风力作用下，当金属细杆OP在图示位置静止时，此时OP与AB接触点恰为AB中点，求出此时作用在球P上的风力的大小。
31．（10分）我们用速度来描述物体运动的快慢，很多时候，物体运动的速度是变化的，例
如：火车进站时，火车的速度越来越小，汽车起步的时候速度越来越大，它们的速度都是变化的，我们定义一个物理量“加速度”来描述物体速度变化的快慢，定义式为
v?v?v2，单位为m/s，其中?v表示速度在时间间隔?t内的变化量，这个比值a?t0??t?t
即为单位时间内速度的变化量，比值越大表示单位时间内速度变化量越大，即速度变化越快，如果a?o，即vt?v0，表示物体做加速运动，同理a?0表示物体做减速运动，我们把加速度确定，即物体的速度是均匀变化的运动称为匀变速运动，由定义式我们可以知道，做匀变速运动的物体某一时刻的速度vt?v0?at，我们已经学过匀速直线运动t时间通过的路程可以用S?vt进行计算，现在提供一个计算匀变速直线运动t时间内路程S的公式：
1S?v0t?at2，试根据上述信息求解以下题目。 2
（1）汽车以10m/S的速度匀速行驶，现以0.6m/s2的加速度加速，10S后速度能达到多少？
在这10S内，汽车经过的路程是多少？
（2）甲、乙两车在同一条平直公路上运动，甲车以10m/s的速度匀速行驶，经过车站A
22时关闭油门，开始做4m/s的匀减速运动，2s后乙车与甲车同方向，以1m/s的加
速度从同一车站A由静止开始作匀加速运动，问乙车出站后经多长时间追上甲车？