问题 实验题

利用如图装置进行“探究动能大小的影响因素”实验。用两根细绳将小球悬挂起来,拉起小球,当细绳与竖直方向成θ角后松手,小球撞击水平木板上的木块,记下木块移动的距离s。改变角度θ的大小,重复实验。

(1)利用如图两根细绳悬挂小球,而不用一根细绳,其好处是   

(2)本实验探究的问题是物体的动能大小与   的关系。

(3)利用上述实验,同时还可以探究的问题是   

答案

(1)便于控制小球的撞击方向(或便于撞准木块等) (2)速度(3)物体重力势能大小与高度有什么关系?或重力势能大小与高度的关系。

题目分析:(1)如图二根细绳控制摆球,能使摆球在同一平面内摆动,便于控制小球的撞击方向。

(2)当细绳与竖直方向成θ角后松手,小球撞击水平木板上的木块,记下木块移动的距离s。改变角度θ的大小,就改变了撞击的速度。

(3)摆球的角度发生变体,它的高度也发生了变体,可以比较物体重力势能大小与高度有什么关系。

单项选择题
阅读理解

阅读理解。

      In 1901, H.G. Wells, an English writer, wrote a book describing a trip to the moon. When the explorers

(探险者) landed on the moon, they discovered that the moon was full of underground cities. They expressed

their surprise to the "moon people" they met. In turn, the "moon people" expressed their surprise. "Why," they

asked, "are you traveling to outer space when you don't even use your inner space?"

      H.G. Wells could only imagine travel to the moon. In 1969, human beings really did land on the moon.

People today know that there are no underground cities on the moon. However, the question that the "moon

people" asked is still an interesting one. A growing number of scientists are seriously thinking about it.

      Underground systems are already in place. Many cities have underground car parks. In some cities, such

as Tokyo, Seoul and Montreal, there are large underground shopping areas. The "Chunnel"-a tunnel (隧道)

connecting England and France, is now complete.

      But what about underground cities? Japan's Taisei Corporation is designed a network of underground

systems, called "Alice Cities." The designers imagine using surface space for public parks and using

underground space for flats, offices, shopping, and so on. A solar dome (太阳能穹顶) would cover the

whole city.

      Supporters of underground development say that building down rather than building up is a good way to

use the earth's space. The surface, they say, can be used for farms, parks, gardens, and wilderness. H.G.

Wells' "moon people" would agree. Would you?

1. The explorers in H. G. Wells' story were surprised to find that the "moon people" ____. [ ]

A. knew so much about the earth

B. understand their language

C. lived in so many underground cities

D. were ahead of them in space technology

2. What does the underlined word "it" (paragraph 2) refer to? [ ]

A. Discovering the moon's inner space.

B. Using the earth's inner space.

C. meeting the "moon people" again.

D. Traveling to outer space.

3. What sort of underground systems are already here with us? [ ]

A. Offices, shopping areas, power stations.

B. Tunnels, car parks, shopping areas.

C. Gardens, car parks, power stations.

D. Tunnels, gardens, offices.

4. What would be the best title for the text? [ ]

A. Alice Cities-cities of the future

B. Space travel with H.G. Wells

C. Enjoy living underground

D. Building down, not up