问题 实验题

某同学在做“探究弹力和弹簧伸长的关系”的实验时,设计了如图甲所示的实验装置。所用的钩码每只的质量都是30 g,他先测出不挂钩码时弹簧的自然长度,再将5个钩码逐个挂在弹簧的下端,每次都测出相应的弹簧总长度,将数据填在了下面的表格中。(弹簧始终未超出弹性限度,取g=10 m/s2

   

(1)试根据这些实验数据,在图乙给定的坐标纸上作出弹簧所受弹力的大小F跟弹簧伸长量△L之间的函数关系图象。

(2)根据图象求出该弹簧的劲度系数k=___________N/m。

(3)另一同学作出的弹簧所受弹力的大小F跟弹簧全长的图象如图丙所示,图象和横轴的截距L0为____________。

答案

(1)

(2)25

(3)弹簧的原长

阅读理解

阅读理解。

     Today people can use the phones to talk with others almost anywhere on the earth. But when you

use the phone, you don't see the person you are talking with. That may change in the near future.

     Today some people are using a kind of telephone called the picture phone or vision phone. With it,

two people who are talking can see each other.

     Picture phone can be useful when you have something to show the person you are calling. They may

have other uses in the future. One day you can ring up a library and ask to see a book. Then you can

read the book with your picture phone. Or you may be able to go shopping through your picture phone.

If you see something in the newspaper that you think you want to buy, you can call the shop. People at

the shop will show you the thing you're interested in by the phone. You will be able to shop all over the

city and never even leave your room!

1. Today people can use the phone to talk with others ______.

A. in all the towns

B. in some places in the world

C. only in big cities

D. almost anywhere on the earth

2. The word "it" in the second paragraph means ______.

A. the picture phone

B. any phone

C. the use

D. the change

3. The writer tells that we can ______  through the picture phone in the future.

A. write a book

B. do shopping

C. play games

D. have classes

4. Picture phones are very ______.

A. useful

B. small

C. bad

D. cheap

5. Which of the following statements (陈述) is not RIGHT?

A. Today some people are using a kind of telephone called the picture phone or vision phone.

B. With the picture phone, two people can't see each other.

C. The picture phone is very useful.

D. Today people can use the phone to talk with others almost everywhere on the earth.

填空题