摘要
本文首先推导出单位失变率的矢量表示式．然后将该式应用于惯性系运动学问题，以球坐标系为例导出了曲线坐标系中速度、加速度的分量表示式，导出了自然轴系中切向加速度和法向加速度的表示式．最后将该式应用于非惯性系运动学问题，在导出绝对变本与相对变率关系的基础上，进而得出绝对运动与相对运动的关系．显示出此种方法在研究运动学问题时的优越性．
In this paper,the general expression for the rate of chnnge of an arbitrary unit vector is derived.Firstly,this expression is applied to the problems in kinematics of inertial system.As an example.with the spherical coordinate system,the expression for components of velocity and acceleration in curvilinear coordinate system are given.Secondly,the expression for tangential and normal accelerations in trihedral axes of a space curve is obtained.Finally,this expression is applied to the problems in kinematics of non-inertial system.The relationbetween absolute rate and relative rate of change is derived.Based on this relation,the relation between absolute and relative motions is set up.It is shown that this approach has the advantage of dealing with the prob-lems in kinematics.
关键词
单位矢
变率
绝对变率
运动学
Unit vector
The rate of change
Absolute rate of change
Relative rate of change
