2017八年级上册物理寒假作业答案
来源:管理学 发布时间:2011-10-23 点击:
2017八年级上册物理寒假作业答案篇一
最新人教版八年级英语上册寒假作业(2017年)
最新人教版八年级英语上册寒假作业(2017年)
Unit 1
姓名________ 学号________ 班级________ 得分________
二、单项选择 (每小题1分,共15分)
( )31. — Where did you go on ____ vacation?— I went to London.
A. a B. an C. the D. /
( )32. Look, the plane is flying _________ the mountain.
A. over B. below C. under D. through
( )33. I ate all the cakes on the table ________ I was hungry.
A. so B. though C. because D. if
( )34. — The soccer game was so ________.— Yes, I felt ________ with it.
A. bored; boring B. boring; boredC. bored; bored D. boring; boring
( )35. __________ like playing basketball and badminton are popular with students.
A. Meetings B. Mountains C. Activities D. Buildings
( )36. Please turn on the TV. I ________ what the weather will be like tomorrow.
A. wonder B. feed C. know D. cross
( )37. — ________ did you go to Guilin with?— My parents.
A. Where B. Who C. When D. How
( )38. We went to our old school last week. It looked the same ________ before.
A. as B. with C. to D. around
( )39. — Why didn’t you get to the top of the mountain?— We didn’t have ________ time.
A. free B. RightC. natural D. enough
( )40. The boy decided _____ back the money to the person who lost it.
A. give B. gives C. to give D. to giving
( )41. — Are you free tomorrow?— Yes, I am. I have ________ to do.
A. anything specialB. special anything C. nothing specialD. special nothing
( )42. — Did he help you with your homework?— No, I did it by __________.
A. I B. me C. mine D. myself
( )43. Bob likes reading. He spends ________ of his free time reading books.
A. few B. any C. little D. most
( )44. — Did everyone enjoy the school trip?— ________. We all had a good time.
A. Yes, they did B. No, they didn’t
C. Yes, we did D. No, we didn’t
( )45. — Did you enjoy the food in China? — ________. It was very delicious.
A. Sounds great B. Of course
C. Good idea D. No problem
三、完形填空 (每小题1分,共10分)
lost it there. He decided to it to the train office. Then the phone rang (响) and he answered, “Hello.” A 49 said, “Hi, this is Michelle. You’re using my phone. I 50 it on the train.” Josh said, “Yes, I found it. And I will take it to the train office.” “Oh, that’s very nice of you. If you leave your address (地址), I would like to post you £20 to you.” Josh said no problem. When the woman came, she got her and a piece of paper (一张纸). Josh left it for
it wasn’t. On the paper she found“Don’t worry about the
( )46. A. train B. bus C. subway D. bike
( )47. A. Anyone B. Someone C. Everyone D. No one
( )48. A. take B. sell C. move D. blow
( )49. A. girl B. boy C. woman D. man
( )50. A. remembered B. left C. bought D. saved
( )51. A. meet B. hear C. visit D. thank
( )52. A. number B. book C. phone D. diary
( )53. A. him B. them C. me D. her
( )54. A. and B. but C. if D. so
( )55. A. money B. time C. place D. people
四、阅读理解(一) (每小题2分,共30分)
A
Do you have any good ways to learn English well? Here are some students talking about ways of learning
A. 3. B. 4. C. 5. D. 6.
( )57. How does Mark learn English?
A. By reading textbooks. B. By reading class notes.
C. By reading English stories. D. By reading English newspapers.
( )58. Who learns English by watching English movies?
A. Mark. B. Jenny. C. Tom. D. Amy.
( )59. What is the best way to learn English according to Tom?
A. Speaking. B. Reading. C. Listening. D. Writing.
( )60. Which of the following is TRUE according to the passage?
A. Jenny and Amy are of the same age.
B. Listening to the radio can help Mark with his English listening.
C. Amy asks us to make full use of our piecemeal time.
D. We have to remember many English words before sleeping.
B
I went on vacation with my family last summer. “Wake up! It’s time to go fishing,” My mom woke me up. After having breakfast we got on a boat. Getting up at 6 a.m. was really early and I was not happy, but later, I had fun. My uncle caught (抓住) a big fish first. And my mom caught one, too. Then I caught a Black Drum. Next, my heard this. Later we tried to catch small sharks (鲨鱼). My grandpa caught one, but it snapped the line (咬断绳子). My uncle caught one, but it also snapped the line. My dad caught one at last. It didn’t look so scary but was
a little funny.
Then our fishing activity was over, and we went back with all the fishes. We were tired but happy!
( )61. Who woke up the writer?
A. His father. B. His mother. C. His uncle. D. His grandpa.
( )62. The underlined word “captain” means “_______” in Chinese.
A. 船长 B. 律师 C. 司机 D. 飞行员
( )63. Why did they feel happy when they heard the captain’s words (话)?
A. Because someone caught a fish the same size as theirs.
B. Because the Black Drum was expensive.
C. Because the fish was the biggest (最大的).
D. Because the boat went very fast.
( )64. How did they feel when they went back with the fishes?
A. Scared. B. Lucky. C. Tired and terrible. D. Tired but happy.
( )65. What does the writer talk about?
A. His summer vacation. B. His favorite fish.
C. His favorite activity. D. His happy family.
C
There is an old dog in Mr. Smith’s family. The dog’s name is Buddy. When Buddy was young, he could run fast and catch many animals. Mr. Smith loved him very much. Now, Buddy is old and weak.
One day, Mr. Smith and Buddy walked into the forest. Buddy saw a pig and caught it, but he was too old and weak and the pig ran away at last.They didn’t get anything that day and went home.
Mr. Smith was not happy. He said to Mrs. Smith, “Buddy is too old. He doesn’t catch anything today.”
Mrs. Smith answered, “Buddy didn’t do anything wrong (错误的). It’s natural for him to get old. For many years, he helped us catch animals and feed our family. So we shouldn’t be angry (生气的) with him.”
Then Mr. Smith knew he was wrong. He said, “I shouldn’t dislike him for being old. I will love him and be good to him just as before.”
( )66. What is Buddy?
A. A dog. B. A mouse. C. A cat. D. A hen.
( )67. Why didn’t Buddy catch the pig?
A. Because he was hungry.
B. Because he was not happy.
C. Because he was old and weak.
D. Because he didn’t want to kill it.
( )68. What did Mr. Smith and Buddy get that day?
A. A sheep. B. A pig. C. Some fruit. D. Nothing.
( )69. Which of the following is TRUE?
A. Buddy worked hard when he was young.
B. Buddy didn’t like catching animals.
C. Mr. Smith didn’t like Buddy when it was young.
D. Mrs. Smith was angry with Buddy.
( )70 What does Mr. Smith want to do?
A. Sell Buddy to the zoo.
B. Give Buddy to his friend.
C. Leave Buddy in the forest.
D. Love and be good to Buddy.
五、单词拼写。(每小题1分,共10分)
71. Let the b_______ fly away. It will be happy.
72. I didn’t w_______ for the bus because it was too late.
73. — Did a____________ go there with you?
— No, I went there myself.
74. I d________ him because he never does his homework.
75. Do you want to buy anything for y________?
76. My Grandma has a ___________ (母鸡) and she likes it very much.
77. This ________ (雨伞) is not mine. It’s Lily’s.
78. I put the ________ (湿的) clothes on the desk just now.
79. There are lots of flowers on the _______ (小山) near my home.
80. We can see the _______ (不同) between the two books.
and I rode 82. _____ every day. There was a little 83. _____ in my grandparents’ home. I fedit every morning. After a few days, it followed me 84. ______ I went. It was really interesting. I heard some 85. ________ stories from my grandpa. When he finished telling a story, he always taught me to learn something from it. I really had a great vacation.
七、阅读理解(二) (每小题2分,共10分)
My name is Lily and I’m thirteen. Many students in our school have interesting hobbies (爱好). Do you have one? If you don’t, you can join the Dance Club.
I started dancing six years ago. I started my hobby because I like dancing. I hope (希望) I can dance on TV one day, so I learned to dance. I also think dancing is a good exercise.
Some people think dancing is boring. Well, I don’t think so. Dancing is a beautiful art and it is fun. If you want to be graceful and elegant (优美端庄的), you can join us.
The Dance Club members (成员) often meet on Mondays after school. You must bring sport clothes to the meeting because we will do some easy exercise before dancing.
If you are interested in dancing, or if you are good at dancing, come and join us!
86. What is Lily’s hobby?
_______________________________________________________________________________
87. How old was Lily when she started dancing?
_______________________________________________________________________________
88. Does Lily think dancing is boring?
_______________________________________________________________________________
89. When do the Dance Club members meet?
_______________________________________________________________________________
90. What must you bring if you go to the meeting?
_______________________________________________________________________________
八、书面表达 (共10分)
假设今天你和你的同学游览了鼓楼和北京胡同,请你根据以下提示,写一篇日记发表在某英文网站上。 提示:
1. Where did you go?
2. What did you like?
3. What did you eat?
4. How did you feel about the visit?
„„
参考词汇:
鼓楼 the Drum Tower; 历史感 a sense of history; 传统的 traditional
要求:
1. 语句通顺、逻辑连贯;
2. 不少于60词。开头已给出,不计入总词数。
Sunday, July 19th
Today it was __________________________________________________________________
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Unit 1参考答案
二、31-35 DACBC 36-40 ABADC 41-45 CDDCB
三、46-50 ABACB 51-55 DCDBA
四、56-60 BCBAC61-65 BACDA 66-70 ACDAD
五、71. bird 72. wait 73. anyone 74. dislike 75. yourself
76. hen 77. umbrella 78. wet 79. hill80. difference
六、81. seemed 82. bicycles 83. duck 84. anywhere 85. wonderful七、86. Dancing. 87. Seven / 7. 88. No, she doesn’t.
89. On Mondays after school. 90. Sport clothes.
八、
Sunday, July 19th Today it was hot and sunny. I went to visit the Drum Tower with my classmate. It was beautiful. And then we walked along a Beijing hutong. We saw some old buildings here. They looked special. I wondered what life was like here in the past. I liked the hutong a lot because it gave me a sense of history. For dinner we tried some traditional Chinese food. It tasted good. In the evening we felt tired and went to bed early.
Unit 2
姓名________ 学号________ 班级________ 得分________
一、听力理解 (略)
二、单项选择 (每小题1分,共15分)
( )31. — What do you often do on ___________ weekends?
— I often go ________ online.
A. the; / B. /; / C. /; the D. the; the
( )32. — Why do you often exercise?
— Because it is good _______ my health.
2017八年级上册物理寒假作业答案篇二
石室初中2017级物理寒假作业(四)
石室初中2015级物理寒假作业(四)
班级________姓名________学号_________
的距离是__________m。当他距镜面1.5m时,一、填空题:(每空1分,共32分)
1、用如图1所示的刻度尺测量物体的长度,读数时,人与像间的距离是__________m。
视线要__________,图示中被测物体的长度为答案:2m,3m __________cm。
7、科学工作者为了探测海底某处的深度,向海底垂
直发射超声波,经过4s收到回波信号,海洋中该处的深度是 m(声音在海水中传播的速
图1 度是1500m/s);这种方法不能用来测量月亮与地
球之间的距离,其原因是
答案:正对刻度线,1.90 ______________________。 2、航天飞机在太空与宇宙空间站对接时,两者在空答案:3000;真空不能传声
中飞行的速度大小和方向必须__________此时8、一辆汽车在水平河岸上行驶,以汽车为参照物,两物体间彼此处于相对__________状态.我国第它在河中的倒影是 ;以河岸为参照物,一列磁悬浮列车最高设计时速达500km/h,如果它在河中的倒影是 。如图3,入射光线乘坐该列车通过40km路程,需要的时间是__与镜面的夹角为30°,则反射角为 ,若___min。 平面镜绕入射点顺时针转动5°,则入射光线与答案:相同,静止,4.8 反射光线的夹角为______。
3、声音是由发声体的__________而产生的。水牛“哞
图3
哞”的叫声和蚊子“嗡嗡”的叫声相比较, 的 叫声音调高, 的叫声的响度大。钢答案:静止的;运动的;60°;130°
琴、吉他、笛子等乐器发出的声音,即使音调、9、光从水中垂直射向空气中时,折射角入射响度都相同,也可以从它们的_________来分辨。 角。老花镜的镜片是 镜。 答案:振动,蚊子,水牛,音色 答案:等于(00),凸透镜
4、中暑是在高温环境下,体温调节不适应,体温上10、照相机是利用的升而头痛、眩晕、恶心.通常情况下,在中暑患原理来工作的。
者身上擦__________对中暑有较好的治疗效果,答案:物体到透镜的距离大于二倍焦距时,成缩小其中的道理是 . 倒立的实像 答案:酒精(或白酒);酒精容易蒸发,蒸发需要吸11、已知冰的密度为0.9×103kg/m3。一块体积是热,使人体温度降低 80cm3的冰全部熔化成水后,水的质量是_____g,5、夏天小潇同学从游泳池出来后,冷的直哆嗦,如水的体积是 cm3。 图这是因为水 ,可他却惊奇的发答案:72,72
现,旁边的一只小狗却热得吐出舌头,快速地喘12.一只小鸟在平静的湖面上飞过,当小鸟距水面着粗气,这是因为吐出舌头和快速喘着粗气,这3m时,小鸟在湖面的“倒影”是_________(填“实”样可以增大 ,并且加快了 或“虚”)像,它是由于光的________形成的,该“倒 ,从而加快了水的蒸发而带影”距小鸟__________m. 走小狗体内多余热量的原因.
答案:虚;反射;6
13.“频闪藏影”是研究物体运动时常用的一种方法,如图所示的底片上记录了两个小球相隔同样时间的不同位置,分析这两个频闪照片可知
图2 两个小球的运动性质为:甲球做的是
运动;乙球做的是 运动.
答案:蒸发吸热;蒸发面积;空气流动
6、某人站在穿衣镜前2m处,他在镜中的像到镜面
1
答案:匀速直线;变速(或加速)直线
14、神舟5号载人飞船返回舱在返回时,虽然表面与大气层剧烈摩擦,就像一个闪亮的火球,但由于表面有一种叫“烧蚀层”的特殊物质在汽化时,能 从而起到保护作用。 答案:吸热
15、将一支蜡烛点燃一会儿后,这支蜡烛的质量将 ,密度将 。 答案:减小,不变
二、选择题(每题2分,共28分)
1、有关误差下列说法中,正确的是
A.误差只能尽量减小,而不能消除 B.测量可以做到没有误差
C.测量中采用多次测量求平均值的方法,可以消灭误差
D.测量中的误差是由于错误而造成的,因此是可以避免的
2、关于声音,下列说法中错误的是
A.声音是由物体的振动产生的 B.噪声不是由物体的振动产生的 C.声音可以在水中传播
图5
D.噪声可以在传播过程中减弱 答案:D
3、为了研究影响蔬菜和水果水分散失快慢的因素,8、将物体放在距凸透镜15cm处时,能在光屏上得有A、B、C、D四组同学各自做了研究实验(实到物体的清晰缩小的像,则凸透镜的焦距可能为 验材料是相同的胡萝卜 ,如图4所示,这四组实A.5cm B.10cm C.15cm D. 20cm 验中,研究方法不正确的是
...9、下列说法中正确的是
A.人走向穿衣镜时人在镜中所成的像逐渐变大 B.黑板“反光”是因为光在“反光”处发生了漫反射 C.激光准直,利用了光沿直线传播的道理
A B C D D.放映电影时银幕上的像是虚像
解:A图中控制的是胡萝卜表面积和胡萝卜上方空10.小迪测量烧杯中热水温度时,将少量热水倒入
另一烧杯中,然后像如图所示的那样去测量和读气流动速度不变,研究的是胡萝卜水分蒸发的快
数,她这样做被小明找出了一些错误,但有一条慢与胡萝卜的温度的关系,研究方法正确;
找得有点问题,请你把它挑出来
B图中控制的是胡萝卜的温度和胡萝卜上方空气流动速度不变,研究胡萝卜水分蒸发快慢与胡萝卜的表面积的关系,研究方法正确;
C图三个因素都相同,不能研究影响胡萝卜水分散失快慢的因素,所以研究方法不正确;
D图中控制的是胡萝卜的温度和表面积不变,研
A.不应倒入另一烧杯,这会使温度降低{2017八年级上册物理寒假作业答案}.
究胡萝卜水分蒸发的快慢和胡萝卜表面空气流动的
2
速度的关系,研究方法正确; 故选C. 4、近年来,许多城市都作出了限放烟花爆竹的规定,其原因主要是燃放烟花爆竹会 A.污染水源 B.产生温室效应 C.污染土壤
D.污染空气、产生噪声,易引发火灾 5、下列物态变化现象中,属于液化的是
A.夏天,剥去冰棒的包装纸,看到“白气” B.洒在教室地上的水变干
C.放入冰箱冷冻室的矿泉水结成了冰 D.冬天,室外冰冻的衣服干了
6、在卫生间里洗过热水澡后,室内的玻璃面变得模糊不清,过一段时间,镜面又变得清晰起来,镜面上发生的两种现象的物态变化情况是 A.先汽化,后液化 B.先液化,后汽化 C.只有液化 D.只有汽化
7、在图5所指出的四个力中,使受力物体运动状态发生改变的是
B.应该将温度计取出读数,而不应该放在水中施中不能减弱噪声的是 ..读数 A.市区内禁止机动车鸣笛 C.水倒得太少,温度计玻璃泡不能完全浸没 B.减少二氧化碳气体的排放 D.读数时,视线应该与温度计玻璃管内液柱上C.在汽车的排气管上装消声器 表面相平,而不应斜视 D.城市街道两旁和空地上多种草、多植树 11、下列说法中错误的是: 17. 物理学中经常用图像来表示物体的运动规律,则
8
A、声音在空气中的传播速度是3×10m/s 下图中能表示同一运动规律的是
B、冬天口呼出的“白气”是水蒸气 C、凸透镜总是将平行光线会聚于焦点 D、从平面镜中只能看到物体的实像
12. 请根据如图所示楼房顶上的旗帜和两船上旗帜
的飘扬情况,判断出甲、乙两船的运动情况
A
.甲船可能向右运动,乙船可能静止 A.甲丙 B.甲丁 C.乙丙 D.乙丁 B.甲船一定向右运动,乙船一定向左运动 18.有一块质量为5kg的铸铁,下列说法中正确的C
.甲船可能向右运动,乙船一定向左运动 是( ) D.甲船一定向右运动,乙船可能向左运动 A. 如果将它从地球带到月球上,它的质量将大13.“影”是我们日常生活中常见的光现象,如做光于5kg 学游戏形成的“手影”,剧院放映的“电影”,湖岸B. 把它化成铁水后,质量小于5kg 景色在水中形成的“倒影”,春游时留下美好记忆C. 把它拉成铁丝后,质量还是5kg 的照片-摄影等,以下列出的“影”与物理知识对D.把它压成铁片后,质量大于5kg 应关系不正确的是 ...19.以下估测中最接近事实的是 A.手影——光的直线传播 A.一张课桌桌面的宽度是5m B.电影——光的直线传播 B.某同学正常的体温是47℃ C.倒影——平面镜成像 C.人步行的速度是1.2m/s D.摄影——光的折射 D.一个乒乓球直径是4dm
14.眼睛是心灵的窗户,关于眼睛及其视力矫正,14.一辆轿车行驶的速度是100km/h,一辆自行车下列说法中正确的是 前进的速度是5m/s,这表明 A.眼睛的晶状体相当于凹透镜 A.轿车行驶的路程一定比自行车多 B.物体通过晶状体所成的像是虚像 B.轿车一定始终在自行车前面 C.远视眼看不清近处景物,是因为景物的像落C.自行车的运动时间一定比轿车长 在视网膜的前方 D.轿车的运动一定比自行车快 D.矫正近视眼所配戴的眼镜镜片是凹透镜 三、作图题(1、3、4每题2分,第2题4分,共15.如图所示,给凸透镜“戴”上近视眼镜,此时光10分) 屏上能成一 清晰的像。若“取”下近视眼镜,为
1、一束光线从空气斜射向水面,在界面处同时发生
使光屏上的像清晰,在保持烛焰和透镜位置不变
了反射和折射,如图6所示,已知反射光线,请的条件下,应该将光屏
作出入射光线的大致的折射光线。
A.靠近透镜 B.保持在原来的位置
C.远离透镜 D.靠近透镜和远离透镜都可以 16.控制噪声是城市环保的主要项目之一,下列措
3
2、完成下列光路图(P为2倍焦距处)
的不便或危害的实例:_____________________。
④如何预防光污染?请你提出一条合理化建议:
答案::(1)平面镜成像是光的反射.
(2)一个几十甚至几百平方米的凹透镜,其聚光功能是相当可观的,这部分是错误的,因为凹透镜对光束是发散的,不可能会聚,作者将凹透镜和凹面镜混淆,显然为一误.
(3)危害居民的身体健康,暴露居民的生活隐
3、如图,由A点发出的很细的一束光线在液面MN私,聚光甚至要引起火灾. 上的O点发生反射,反射光线的小光斑在B点(图(4)要限制开发商在居民区造商务大楼.对玻中PQ与MN平行)。由于液面高度的变化,反射璃墙的设计、制作及使用范围要有统一的技术标准,
′
光斑由B点移到B点,试作出液面变化的高度。
防止光污染进入居民家或公共设施内.
五、实验题
1、如图是《观察水的沸腾》实验,以下步骤中有错
误的是 (
)
四、简答题(共8分)
1、下面是摘自某刊物的文章,请仔细阅读后,按要求回答问题:
《光污染,来自靓丽的玻璃幕墙》
最近,张小姐十分苦恼,因为她的房子正对着一座新大厦的玻璃幕墙。有时站在她家的窗前,看到对面玻璃幕墙就像平面镜一样,将同楼居民家的一举一动看得清清楚楚。玻璃幕墙的反光也使她苦不堪言,只要是晴天,她的房间就被强烈的反射光线照得通亮,无法正常休息。尤其是那种凹形建筑物,其玻璃幕墙在客观上形成一种巨型聚光镜,一个几十甚至几百平方米的凹透镜,其聚光功能是相当可观的,能使局部温度升高,造成火灾隐患„„ ①从文中找出一个光学方面的物理知识填入横线:_______________________________。
②文中有一处出现了科学性错误,请在错误句子下面画上横线。
③从上文中找出一个玻璃幕墙给居民生活带来
4
A.把水倒在烧杯里,把温度计穿过纸板插到杯底
B.用酒精灯给盛水的烧杯加热
C.当水温升到90℃时,每隔1分钟记录1次水的温度,直到水沸腾后5分钟为止 D.根据记录作出水的沸腾图象
解:A.把水倒在烧杯里,把温度计穿过纸板插到杯底,温度计的玻璃泡不能碰到容器底或壁,这种操作是错误的.
B.用酒精灯给盛水的烧杯加热,水从酒精灯吸收热量.操作正确. C.当水温升到90℃时,每隔1分钟记录1次水的温度,直到水沸腾后5分钟为止,为了获得水沸腾前和沸腾时的温度.操作正确.
D.根据记录作出水的沸腾图象,观察水沸腾前和沸腾时,温度的变化.操作正确. 故答案为:A.
2、在“用天平和量筒测定固体和液体的密度”实验中,为测定物体的质量,调节天平横梁平衡时,
发现天平的指针静止在分度盘中央刻度线的左六、综合题
侧,则应将横梁上的平衡螺母向_______调节,1、从湛江飞往北京的3141航班的飞机,上午从湛将一矿石标本放在已调好的天平左盘内,当天平江起飞,当天下午到达北京,全程行程2700km,重新平衡时右盘内的砝码和游码在标尺上的位此航班飞行时刻如下表所示,求全程的平均速置如图甲所示,则矿石的质量为_______g,将矿度。 石标本放入装有水的量筒中,量筒中水面位置的变化情况如图乙所示,则矿石的体积为
____cm3.这种矿石的密度为_______kg/m3.
解:(1)由表可得;从湛江飞往北京的时间 t=16:00-11:30=4.5h
湛江飞往北京的路程 s=2700km
3
由公式
答案:右。64,30,3.2×10
3、欲对一块形状不规则的矿石标本进行鉴定,请你
利用所学知识设计两种测矿石密度的方法,将每2、一块石碑的质量是78t,为计算它的体积,找一种方法所需的主要器材和应测量的物理量填在块相同的石块作样品,用天平称出样品的质量是下表中。 130g,放入装有80mL的水的量筒中升至130mL
处,求:①这块石碑的物重;②这块石碑的体积。 解:(1)石碑的物重 G=mg=78×103kg×10N/kg=7.8×104N (2)石碑样品的体积{2017八年级上册物理寒假作业答案}.
V样=130mL-80mL=50mL=5×10-5m3 石碑的密度
s
得全程的平均速度 t2700km600km/h
4.5h
解:根据实验的主要依据
想办法测出矿石的V
质量和体积,是我们的主要思路.具体器材与相应物理量见下表
主要实验器材
实验中应测量的物理量
m样13010-3kg
=2.6×103kg/m3 53
V样510m
石碑的体积
1.矿石的质量m
方法一
天平、量筒、细线、水
2. 矿石放入前量筒中水的体积V1
3.矿石放入量筒后矿石和水的总体积V2 1.矿石的重力G
方法二
弹簧测力计、量筒、细线、水
2. 矿石放入前量筒中水的体积V1
3.矿石放入量筒后水和矿石的总体积V2
7.8103kg3
V 3m33
2.610kg/m
m
5
2017八年级上册物理寒假作业答案篇三
高一物理寒假作业二2017.1.8
高一物理寒假作业二
组卷人:施叶军 审核人:裘金亚
一、单项选择题
1.下列单位中,属于国际单位制大的基本单位是( )
A.千克 B.牛顿 C.米每秒 D.小时
2.下列所说的速度中,是平均速度的是
A.百米赛跑的运动员以9.5 m/s的速度冲过终点线
B.返回地面的太空舱以8 m/s的速度落至太平洋洋面
C.子弹以800 m/s的速度撞击到墙上
D.由于堵车,从新南门到磨子桥汽车的速度仅为 4 km/h
3.以一定的初速度沿光滑的斜面上滑的物体受到的力是( )
A.重力、牵引力和斜面的支持力
B.重力、摩擦力和斜面的支持力
C.重力和斜面的支持力
D.重力、支持力、牵引力和压力
4.在探究“弹力与弹簧伸长的关系”试验中,测得轻质弹簧的原长为l0=9 cm.当弹簧所受拉力为F1=0.5 N 时,弹簧的长度为l1=11 cm,当拉力为F2=1 N时,弹簧的长度为l2=13 cm.则该弹簧的劲度系数为( )
A.4 cm/N B.25 N/m C.4.6 N/m D.0.04 m/N
5.为了测量篮球从某一高度自由下落着地时对篮球的最大弹力,一位同学采取了如下方法:把一张平白纸放在地面,在篮球的表面均匀地洒上水,让篮球从特定高度自由落到白纸上,在纸上留下水印;然后把这张纸放到体重计上,将篮球放在纸上,慢慢地向下压,直至球面和水印重合,此时读出体重计的示数,即可知地面对篮球的最大弹力的大小.以下试验中所用的方法与此相类似的是( )
A.在研究弹簧弹力与伸长关系时,弹簧不超过弹性限度
B.在研究加速度与合外力关系时,保持物体的质量不变
C.在验证力的平行四边形定则时,两次将橡皮条拉长至同一位置
D.在观察桌面受到压力发生微小形变的实验中,使用激光笔和平面镜
6.如图所示,小李在公园游玩时将吊床用绳子拴在两棵树上等高位置,他先坐在吊床上,静止时两绳与竖直方向的夹角为θ1;然后他躺在吊床上,静止时两绳与竖直方向的夹角
为θ2,已知θ1>θ2,设吊床对小李的作用力为F1,吊床两端系绳中的拉
力为F2、则( )
A.坐着比躺着时F1大
B.躺着比坐着时F1大
C.躺着比坐着时F2大
D.坐着比躺着时F2大
二、不定项选择题
7.下列说法中,能找到相应实例的是( )
A.物体运动的位移不等于0,而路程等于0
B.物体运动的加速度等于0,而速度却不等于0
C.物体速度变化越来越快,而加速度却越来越小
D.物体的速度变化量较大,而加速度却较小
8.成都市某中学科技研究小组设计了一种测定风力的仪器,原理如图所示,它的细长金属丝一端固定于悬点O,另一端悬挂一个质量为m
的金属球.无风时,金属丝自然下垂,当受到沿水平方向吹来的风时,
金属丝将偏离竖直方向角度θ.风力越大,偏角越大.下列关于风力F、金属丝弹力T、偏角θ、小球质量m之间的关系式正确的是( )
A.T=mg sin θ B.T=mgcos θ C.F=mg tan θ D.F=mg cot θ
9.一个质量为2kg的物体,在6个共点力的作用下保持静止.若同时撤销其中大小分别为18N和12N的两个力,其余的力保持不变,此时该物体的加速度大小可能是( )
A.13 m/s2 B. 3 m/s2 C.2 m/s2 D.16 m/s2
10.某质点沿x轴做直线运动,其v-t图像如图所示,质点在t=0时位于
x=2 m处,开始沿x轴正向运动,则 ( )
A.t=0.5 s时,质点的加速度方向与速度方向相反
B.t=3.5 s时,质点的加速度方向与速度方向相反
C.t=4 s时,质点在x轴上的位移为x=6 m
D.t=8 s时,质点在x轴上的位移为x=11 m
11.如图所示,物块M在静止的传送带上以速度v匀速下滑时,传送带突然起动,方向如图箭头所示,若传送带的速度大小也为v,则传送带起动后( )
A.M静止在传送带上
B.M可能沿斜面向上运动
C.M下滑的速度减小
D.M受到的摩擦力不变
12.如图所示,小车向右运动的过程中,某段时间内车中悬挂的小球A和车水平底板上的物块B都相对车
厢静止,悬挂小球A的悬线与竖直线有一定夹角θ,B与车底板之间的动摩擦因数为0.75,假设B所受最大静摩擦力等于滑动摩擦力.在这段时间内,下述判断中正确的是( )
A.物块B不受摩擦力作用
B.物块B受摩擦力作用,大小恒定,方向向左
C.要使A、B和车保持相对静止,θ最大为37°
D.要使A、B和车保持相对静止,θ最大为53°
三、实验题
13.小李同学用纸带和打点计时器研究小车的运动,小车拉着纸带由右向左运动.他在打出的只带上选择了6个计数点A、B、C、D、E、F,如图所示,相邻两个计数点的时间间隔为 0.1 s,各点到A点的距离依次是 2.0 cm、5.0 cm、9.0 cm、14.0 cm、20.0 cm.请根据题意
完成以下问题:
(1)打下B点时小车的速度为 vB =____________m/s
(2)根据纸带可得小车运动的加速度为____________m/s2.
14.(1)通过两个定滑轮,用两根细线去拉伸一根一端固定在墙上的橡皮筋OP.过定滑轮A的线挂三个砝码,过定滑轮B的线挂四个砝码,两根细线都系在橡皮筋的P端,在两个拉力的共同作用下,使橡皮筋从P点水平地拉伸到P'点,此时两根细线的夹角为90°,如图甲所示.如果改用一根细线,绕过一个定滑轮,要取得同样的效果,定滑轮必须安装在_____________________,线上挂________个砝码.
`{2017八年级上册物理寒假作业答案}.
(2)某同学在做“验证力的平行四边形定则”实验时,利用坐标纸记下了橡皮筋的结点位置O点以及两只弹簧测力计拉力的大小,如图乙所示.请在图中作出F1和F2的合力图示,并用F表示此力.
15.甲图所示为“用DIS(位移传感器、数据采集器、计算机)研究加速度和力的关系”的实验装置. 位移传感器
(发射器) 位移传感器(接收器)
乙
(1)在该实验中必须采用控制变量法,应保持_________不变,用钩码所受的重力作为小车所受的外力,用DIS测小车的加速度.
(2)改变所挂钩码的数量,多次重复测量.在某次实验中根据测得的多组数据可画出a-F关系图线(如以图所示).
①分析此图线的OA端可得出的实验结论是_______________________________.
②此图线的AB段明显偏离直线,造成此误差的主要原因是( )
A.小车与轨道之间存在摩擦 B.导轨保持了水平状态
C.所挂钩码的总质量太大 D.所用小车的质量太大
四、计算题
16.为进一步增强市民文明交通的意识,2014年成都市曝光各种不文明的交通行为.某天在市区内有一辆车遇到有人闯红灯,马上紧急刹车,经时间 t=1.5 s停止,测得路面刹车的痕迹长 x=4.5m,刹车后车的运动为匀减速直线运动,则刹车过程的加速度a的大小是多少?初速度 v0 是多少?若此道路规定,车辆行驶的速度不得超过 30 km/h,试问这辆车是否违章?
17.成都欢乐谷的“跳楼机”游戏,既新奇又刺激,很受同学们 欢迎.其原理是将巨型娱乐器械由升降机送到离地面 60 m 的 高处,然后让座舱自由下落,落到离地面 20 m 高时,制动系统
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