题型:问答题 做圆轨道上稳定运行的飞船内,宇航员为了验证向心力公式,设计了如图所示的装置(图中O为光滑的小孔):给待测物体一个初速度,使它在水平桌面上做匀速圆周运动.该飞船内具有基本测量工具.(1)实验时需要测量的物理量是______;(写出描述物理量的文字和符号)(2)若向心力公式成立,则上述物理量的关系式:______. 查看答案
题型:选择题 His daughter advised him to _____ smoking and at last he _____ to her. [ ]A. give up; gave in B. give in; gave up C. give away; gave in D. give out; gave up 查看答案