问题 问答题

一辆汽车沿平直公路以V0= 10m/s匀速运动,忽然以加速度为2m/s2刹车,求汽车刹车后6s内的位移是多大?

 

答案

25m

设汽车刹车后到停止运动用时,则:

    可得:

="5" s

因为t=12s>="5" s

所以汽车刹车后12s的位移就是前5s的位移  

S=

改错题

短文改错(共10小题,每小题1分,满分10分)

此题要求改正所给短文中的错误。对标有题号的每一行做出判断:如无错误,在该行右边的横线上划一个“√”如有错误(每行只有一个错误),则按下列情况改正:

该行多一个词:把多余的词用斜线(╲)划掉,在该行右边横线上写出该词,并也用斜线划掉。

该行缺一个词:在缺词处加一个漏字符号(∧),在该行右边横线上写出该加的词。

该行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。

注意:原行没有错的不要改。

This summer holiday, I get a chance to teach English              76. ___________

beginners. I experienced life as teacher for the first time.              77. ___________

The students were very small, but I was even nervous when                  78. ___________

so many kids stared at me. Fortunately, their warmly welcome            79. ___________

encouraged me. I taught them some letters, sang English songs                  80. ___________

and played games with them, fill the classroom with laughter.               81. ___________

But little kid like talking with each other in class, so it was             82. ___________

hard to control the class. As a result, I got a sore throat. Thus,            83. ___________

I found that teaching is cool and exciting, especially that                84. ___________

when you help your students to learn anything with joy.                  85. ___________

实验题