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问题 实验题

一同学在距离地面45 m的高度处水平投掷一物体，已知物体落地时的水平位移为90 m，则物体抛出时的水平速度是________________m/s.

答案

30

根据h=gt2，得物体的运动时间t=="3" s

物体抛出时的水平速度v0= m/s="30" m/s.

阅读理解

阅读理解。

     Events Time Information about Players

The girls' 400-meter race 8:00 a. m. Ten girl runners from Grade Two will be in the girls' 400-meter race. Among these runners, both Li Li and Han Wei run very fast. Maybe they will have equal (均等的) chance to win the first place.

     The long jump 9:15 a. m. All the players are very good. However, two players, Wang Liang and Ma Ming, from Class Two, Grade Three are better than any other player. Last sports meet they were both in the first place, The shot-put event 2:10 p. m. More than twelve players will take part in this event. They are all very strong and everyone has a good record. Li Feng is the best of all the players. His best record is 16. 7 meters and the school record is his. No one has broken this record so far. The relay race 4:00 p. m. It will be an expecting race. All the runners are good at running, It's difficult to say which class will be the winner.

1.1f you arrive at the ground at 8:30 a. m. ,you can watch        .

A. the girls' 400-meter race    

B. the long jump

C. the shot-put event        

D. the relay race

2. According to the writer,which class may win the long jump ?

A. Class l.                

B. Class 2.

C. Class 3.                

D. Class 4.

3. Who is the best player in the shot-put event?

A. Li Feng.                

B. Wang Liang.

C. Ma Ming.                

D. Li Li.
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问答题 简答题

回路分界点设施归属如何划分？
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