问题 问答题

我校高一学生在做“研究平抛运动”的实验时:

(1)研究平抛运动,下面哪些做法可以减小实验误差______

A.使用密度大、体积小的钢球

B.尽量减小钢球与斜槽间的摩擦

C.实验时,让小球每次都从同一高度由静止开始滚下

D.使斜槽末端的切线保持水平

(2)在做本实验时,让小球多次沿同一轨道运动,通过描点法画小球做平抛运动的轨迹,为了能较准确地描绘运动轨迹,下面列出了一些操作要求,将你认为正确的选项前面的字母填在横线上:______.

A.通过调节使斜槽的末端保持水平

B.每次释放小球的位置必须不同

C.每次必须由静止释放小球

D.用铅笔记录小球位置时,每次必须严格地等距离下降

E.小球运动时不应与木板上的白纸(或方格纸)相触

F.将球的位置记录在纸上后,取下纸,用直尺将点连成折线

(3)如图1是某实验小组描绘出的小球做平抛运动的轨迹,P点轨迹上的一点,根据图中数据,小球做平抛运动的初速度是______m/s

(4)某小组同学由于疏忽,忘记记下斜槽末端位置,如图2中的A点为小球运动一段时间后的位置,他便以A点为坐标原点,建立了水平方向和竖直方向的坐标轴,得到如图所示的图象.试根据图象求出小球做平抛运动的初速度大小为______m/s.

答案

(1)A、使用密度大、体积小的钢球可以减小做平抛运动时的空气阻力,故A正确;

B、该实验要求小球每次抛出的初速度要相同而且水平,因此要求小球从同一位置静止释放,至于钢球与斜槽间的摩擦没有影响,故B错误;

C、为确保有相同的水平初速度,所以要求从同一位置无初速度释放,故C正确;

D、实验中必须保证小球做平抛运动,而平抛运动要求有水平初速度且只受重力作用,所以斜槽轨道必须要水平,故D正确.

故选:ACD.

(2)A、通过调节使斜槽末端保持水平,是为了保证小球做平抛运动.故A正确.

B、因为要画同一运动的轨迹,必须每次释放小球的位置相同,且由静止释放,以保证获得相同的初速度,故B错误,C正确.

D、因平抛运动的竖直分运动是自由落体运动,在相同时间里,位移越来越大,因此木条(或凹槽)下降的距离不应是等距的,故D错误.

E、做平抛运动的物体在同一竖直面内运动,固定白纸的木板必须调节成竖直,小球运动时不应与木板上的白纸相接触,以免有阻力的影响,故E正确;

F、将球经过不同高度的位置记录在纸上后,取下纸,平滑的曲线把各点连接起来,故F错误;

故选:ACE.

(3)在竖直方向上,小球做自由落体运动,y=

1
2
gt2,则t=
2y
g
=
2×0.2
10
=0.2s,

小球的水平方向匀速直线运动,小球的初速度v0=

x
t
=
0.1
0.2
=0.5m/s;

(4)在竖直方向上有:△y=gT2,则T=

△y
g
=
(0.75-0.4)-(0.4-0.15)
10
s=0.1s.

则v0=

x
t
=
0.2
0.1
=2m/s

故答案为:(1)ACD;(2)ACE;(3)0.5;(4)2.

阅读理解

As more and more people speak the global languages of English, Chinese, Spanish, and Arabic, other languages are rapidly disappearing. In fact, half of the 6,000-7,000 languages spoken around the world today will likely die out by the next century, according to the United Nations Educational, Scientific, and Cultural Organization (UNESCO).

In an effort to prevent language loss, scholars from a number of organizations- UNESCO and National Geographic among them –have for many years been documenting dying languages and the cultures they reflect.

Mark Turin, a scientist at the Macmillan Center, Yale University, who specializes in the languages and oral traditions of the Himalayas, is following in that tradition. His recently published book, A Grammar of Thangmi with an Ethnolinguistic Introduction to the Speakers and Their Culture, grows out of his experience living, looking and raising a family in a village in Nepal.

Documenting the Tangmi language and culture is just a starting point for Turin, who seeks to include other languages and oral traditions across the Himalayans reaches of India, Nepal, Bhutan, and China. But he is not content to simply record these voices before they disappear without record.

At the University of Cambridge Turin discovered a wealth of important materials- including photographs, films, tap recordings, and field notes- which had remained unstudied and were badly in need of care and protection.

Now, through the two organizations that he has founded-the Digital Himalaya Project and the World Oral Literature Project- Turin has started a campaign to make such documents, found in libraries and stores around the world, available not just to scholars but to the youngers.

Generations of communities from whom the materials were originally collected.Thanks to digital technology and the widely available Internet. Turin notes,the endangered languages can be saved and reconnected with speech communities.

小题1:Many scholars are making efforts to _____.

A.promote global languages

B.rescue the disappearing languages

C.search for language communities

D.set up languages research organizations.小题2:What does “that tradition” in Paragraph 3 refer to?

A.Having first records of the languages

B.Writing books on language searching

C.Telling stories about language users

D.Linking with the native speakers小题3:What is Turin’s book based on?

A.The cultural statics in India.

B.The documents available at Yale.

C.His language research in Britain.

D.His personal experience in Nepal.小题4:Which of the following best describe Turin’s  Work?

A.Write sell and donate.

B.Record,repeat and reward.

C.Collect,protect and reconnect.

D.Design, experiment and report.

问答题 简答题