问题 填空题

一个物体受到8N的力的作用时,产生的加速度是4m/s2.要使它产生6m/s2的加速度,需要对它施加的力的大小是______N.

答案

根据a=

F
m
,得m=
F
a
=
8
4
kg=2kg
.则F′=ma′=2×6N=12N.

故答案为:12.

单项选择题 B型题
阅读理解

阅读理解。

      Last year when Tom graduated from school, he came to Taibei. He didn't like to work on his father's

farm and hoped to find a job in a big city. He went from one company to another but no one wanted him.

With little money left, he got to the station, sad and tired. All he wanted to do was go back to his small town.

It was very late at night and the station was full of people. They were waiting to buy tickets of the last train.

He bought the last ticket, and he was very happy.

      At that time, a woman with a crying baby walked to him and asked him to sell her the ticket. He gave

her the ticket because he thought they needed it more than he did. After the train left, he sat on the bench

and didn't know where to go. Suddenly, an old man came and said, "Young man, I have seen what you did

to the woman. I am the owner of a big company. I need a good young man like you. Would you like to

work for me?"

1. Tom came to the station to _____. [ ]

A. find a job

B. take the train home

C. sell the ticket

D. take the train to Taibei

2. The woman walked to Tom because _____. [ ]

A. she was Tom's old friend

B. her child wanted to talk to Tom

C. she needed to take the train

D. she had no money to buy a ticket

3. Tom didn't take the train because _____. [ ]

A. he didn't take a train ticket

B. he missed the train

C. he wanted to talk to the old man

D. he gave his ticket to the woman

4. The old man wanted to _____. [ ]

A. lend Tom some money

B. give Tom a job

C. say "Thank you" to Tom

D. sit on the bench with Tom

5. What can we learn from this story? [ ]

A. Many people find job in a train station.

B. Don't buy the last ticket of the train.

C. If we try our best to help others, others will help us.

D. We should not give our ticket to others in a train station.