a subway train starting from rest along a straight track has a uniform acceleration of 1.8m/s2 for t

a subway train starting from rest along a straight track has a uniform acceleration of 1.8m/s2 for t

题目
a subway train starting from rest along a straight track has a uniform acceleration of 1.8m/s2 for the first 20m it travels.
a.calculate its speed when it has traveled 10m.
b.When it has traveled 20m,will its speed be less than double,double,or more than double its speed at 10m?
c.Now calculate its speed when it has traveled 20m .Does this agree with you answer B
答案
题目说的是火车从静止开始 做加速度1.8m/s^2的直线运动.1.计算10m时的速度2.当运行了20m,火车的速度和10m的2被什么关系、大于?小于?3.计算20m的速度,是否和你在2中选择的一样.S=Vt^2/2a10m时候的速度Vt=6m/s20m时候...
举一反三
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
奥巴马演讲不用看稿子.为什么中国领导演讲要看?
想找英语初三上学期的首字母填空练习……
英语翻译
1,人们染上烟瘾,最终因吸烟使自己丧命.
最新试题
热门考点

超级试练试题库

© 2017-2019 超级试练试题库,All Rights Reserved.