问题 实验题

像打点计时器一样,光电计时器也是一种研究物体运动情况的常用计时仪器,其结构如图甲所示,a、b分别是光电门的激光发射和接收装置,当有物体从a、b间通过时,光电计时器就可以显示物体的挡光时间。现利用图乙所示装置测量滑块在长1 m左右的木板上运动的速度,乙图中MN是水平桌面,Q是木板与桌面的接触点,1和2是固定在木板上适当位置的两个光电门,与之连接的两个光电计时器没有画出,此外在木板顶端的P点还悬挂着一个铅锤,让滑块从木板的顶端滑下,光电门1、2各自连接的计时器显示的挡光时间分别为5.0×10-2 s和2.0×10-2 s。用游标卡尺测量小滑块的宽度d=5.015 cm。则:

(1)滑块通过光电门1的速度v1=____m/s;

(2)滑块通过光电门2的速度v2=____m/s。

答案

(1)1.003

(2)2.508

阅读理解

Mrs. Black was a poor old woman and she lived in a small village. Her husband died ten years ago. But she had a 24-year-old daughter. Her name was Alice. She worked in New York and lived there. It was far away from her mother's village, and she was not happy about this. One day Alice said to her mother, "I've found a good job in Boston, and I can make a lot of money there, so I will go to work in Boston next week. But don't worry, Mum. I'll send you some money every week. "

A month later, Mrs. Black was very angry. She decided to go to see her daughter in Boston on a train. When she saw her daughter, she said, "Alice, why do you never call me?"

Alice laughed, "But mother," she said, "you haven't got a telephone."

"No", she answered, "I haven't, but you have got one. "

小题1:Mrs. Black lived __________.

A.in Canada

B.in Australia

C.in England

D.in America小题2:Mrs. Black lived __________.

A.alone

B.with her husband

C.with her daughter

D.with her mother小题3:Alice decided to work in Boston because __________.

A.New York was too far from her mother's village

B.Boston was near her mother's village

C.she had found a good job there

D.she thought Boston was a quiet and nice place小题4:A month later, Mrs. Black went to see her daughter in Boston __________.

A.by air

B.by train

C.by bus

D.by sea小题5:Alice had never telephoned her mother because __________.

A.she didn't have time to do so

B.her mother didn't have a telephone

C.she didn't want to spend money on calling

D.her mother didn't know how to make a telephone call

单项选择题