Bilingual edition: English is preserved and Chinese follows each unit. Terminology uses the confirmed v20260916 glossary; automated semantic review remains traceable.
中英双语版：英文原文完整保留，中文紧随对应单元；术语采用 v20260916 确认表，自动语义审校结果可追溯。

Basic Vector Definitions

基本矢量定义

A vector is a quantity that has both magnitude and direction. The magnitude is a scalar quantity, a scalar being defined as a quantity which may be completely specified by a number and perhaps a unit. Common textbook representations of vectors include boldfaced letters and boldface with an arrow above them. For example a displacement vector of 30 meters east could be represented in a variety of ways:

The magnitude of the vector might be represented by absolute value signs around the vector symbol, or just the letter without the boldface.

A vector might also be expressed in terms of unit vectors.

矢量是一种既有大小又有方向的量。大小是一个标量，标量被定义为可以完全由一个数值和可能的单位来指定的量。教科书中的常见矢量表示方法包括粗体字母和箭头上方的粗体符号。例如，一个向东的30米位移矢量可以有多种表示方式：矢量的大小可能用矢量符号周围的绝对值符号表示，或者仅用字母本身表示，而不带粗体。矢量也可以用单位矢量来表示。
 Index

Vector concepts
索引矢量概念
 
HyperPhysics****HyperMath*****Vectors
HyperPhysics **** HyperMath ***** 向量
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Unit Vectors

单位向量

It is convenient to use vectors of unit length to specify the directions of vector quantities in the various coordinate systems. In cartesian coordinates it is typical to use i, j and k to represent unit vectors in the x, y and z directions respectively. A vector which specifies a position in space with respect to the origin of the coordinate system could then be written.

使用单位长度的矢量来指定不同坐标系中矢量量的 direction 是很方便的。在笛卡尔坐标系中，通常用 i, j 和 k 分别表示 x, y 和 z 方向的单位矢量。然后，一个指定相对于坐标系原点在空间中的位置的矢量就可以写成。
 Index

Vector concepts
索引矢量概念
 
HyperPhysics****HyperMath*****Vectors
HyperPhysics **** HyperMath ***** 向量
R Nave
 Go Back
返回