问题 问答题

某同学通过实验探究“物体的重力势能跟物体的质量、高度的关系”时,得到如表二所示的实验数据.(g取10N/kg)

(1)根据______三次实验数据可知:质量一定时,物体的重力势能跟被举起的高度成正比.

(2)根据______三次实验数据可知:高度一定时,物体的重力势能跟它的质量成正比.

(3)第6、7两次部分实验数据不慎擦掉了,请你补充在表中的空格内.

序号质量m/kg高度h/m重力势能/J
11.00.55
21.01.010
32.00.510
43.00.515
51.01.515
6______0.545
71.0______45

答案

(1)实验1、2、5,质量相同,高度增加到原来的n倍,重力势能增大到原来的n倍,所以实验1、2、5得到:质量一定时,物体的重力势能跟被举起的高度成正比.

(2)实验1、3、4,高度相同,质量增大到原来的n倍,重力势能增大到原来的n倍,所以实验1、3、4得到:高度一定时,物体的重力势能跟它的质量成正比.

(3)实验序号6:根据高度一定时,物体的重力势能跟它的质量成正比.由实验4和6得,高度不变,重力势能增大到原来的3倍,质量增大到原来的3倍,所以质量是9kg.

实验序号7:根据质量一定时,物体的重力势能跟被举起的高度成正比.由实验5和7得,质量不变,重力势能增大到原来的3倍,高度增大到原来的3倍,所以高度是4.5m.

故答案为:(1)1、2、5;(2)1、3、4;(3)9;4.5.

阅读理解

The Mississippi is the major river system in the United States. The Yangtze is China’s longest river.

Although a world apart, the two waterways share conservation concerns that provide a cultural bridge between students in the United States and China, as well as from around the world.

The Mississippi flows almost 3,800 kilometers from a small lake in Minnesota, gathering the waters of 250 other rivers and streams before reaching the Gulf of Mexico.

In mid-May, as spring flowers began to open, about 41 students from a dozen colleges, mostly in the Midwest, explored a section of the river in Wisconsin and Iowa, to learn about the environment, and each other.

The students, from the U.S., China and around the world, came to join the River Spirit Exchange program.

The cross-cultural educational experience - set up by the University of Wisconsin, Madison-based Environment and Public Health Network for Chinese Students - focuses on the Mississippi and China’s longest river, the Yangtze.

This three day get-together featured story-telling, hiking, camping and canoeing, all part of a larger lesson about conservation projects that can be used on both the Yangtze and Mississippi.

While the students learned about the problems challenging the Mississippi and Yangtze, Jeb Barzen, a wildlife biologist, explained they should also learn about the importance of bridging each other’s culture.

The president of the Environment and Public Health Network for Chinese Students, Xiaojun Lu, said the Mississippi and Yangtze Rivers are uniting these students from opposite ends of the earth.

Organizers say the success and spirit of this first gathering of students will lead to other trips, including one down the Yangtze.

小题1:Where is the source of the Mississippi?

A.Minnesota

B.the Gulf of Mexico

C.Wisconsin

D.Iowa小题2: According to the passage, the get-together             .

A.lasted a week

B.took place in May

C.was held in China

D.was organized by students小题3: According to Paragraph 8, Barzen believes that             .

A.China and the U.S. should work together to protect the environment

B.the Mississippi is more important than the Yangtze to the world

C.cultural exchange between different countries is of great importance

D.the program encourages technical cooperation between China and the U.S.小题4:What is the passage mainly about?

A.A major river system in the United States.

B.The differences between the Mississippi and the Yangtze.

C.An educational program about tourism.

D.An international cultural exchange program.小题5:Where is the passage most probably taken from?

A.A personal diary

B.A news report

C.An official document

D.An advertisement

单项选择题 A3型题