问题 实验题

(4分)在探究牛顿第二定律实验中采用下图a的装置,通过改变重物的质量,利用计算机可得滑块运动的加速度a和所受拉力F的关系图像。他们在轨道水平和倾斜的两种情况下分别做了实验,得到了两条a-F图线,如图(b)所示。(g=10

滑块和位移传感器发射部分的总质量m=_________kg;滑块和轨道间的动摩擦因数

μ=         

答案

0.5  0.2

题目分析:上面直线的函数关系是,图线的斜率为,在外力为零时,存在加速度,说明是轨道是倾斜的,

函数关系是,图线的斜率也为,此种情况轨道是水平的,

倾斜程度(斜率)一样,说明滑块和位移传感器发射部分的总质量在两种情况下是一样的,故,所以质量为0.5kg,

将(1、0)带入可得

阅读理解

All young people dream of travelling the world. They are restless and very eager to see new sights. However, they have little idea how they would really do it if given the chance. Because their knowledge of geography is quite limited, they seldom know much about the places they wish to visit or how they would get there.

Already hundreds of thousands of Chinese student tourists are visiting these places-Wuyi, Lhasa, Lijiang, Dali, Vientiane and Phnom Penh. Indeed, these students will soon be the most travelled generation in China’s long history. The World Tourist Organization predicts that a quarter of a century from now the number of Chinese tourists going abroad will be twenty times what it is today. The largest percentage of these tourists will visit Southeast Asia. Not all Chinese who travel abroad will be tourists, however. More and more youths are deciding to volunteer their skills in this region; much like their peers in th-e Peace Corps and VSO.

Critical thinking skills required include planning for a trip and solving problems after the trip has begun. The focus is on how to read an atlas (地图集) to make travel plans and how to find ways of travelling. An atlas offers a wealth of information about geography and is one way to increase students’ awareness of their global environment. Use of an atlas especially addresses the needs of students with different visual and spatial (空间的) learning styles.

71.The main idea. of the first paragraph is ________.

A. all young people wish to travel around the world

B. all young people like to learn the knowledge of geography

C. all young people like travelling but their knowledge of geography is quite limited

D. all young people are aware of the places they are going

72. These places, Wuyi, Lhasa, Lijiang, Dali, Vientiane and Phnom Penh, lie in ________.

A. China         B. Europe         C. Vietnam         D. Asia

73.Which of the following statements is TRUE?

A. The number of Chinese tourists going abroad will be twenty times what it is today in about 25 years.

B. The number of Chinese tourists going abroad will be twenty times what it is today in .about 10 years.

C. Southeast Asia will become the most popular visiting place in the world.

D. Young people will be addicted to Internet travelling.

74.One way to increase students’ awareness of their global environment is for them to ________.

A. watch TV         B. listen to radio news   C. read an atlas           D. plan a trip

75.The underlined phrase “a wealth of” can be replaced by “_________”.

A. a number of       B. a great many   C. a great many of      D. a great deal of

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