Unit 9 Computer virus Text 1 Virus Introduction Viruses will cause much confusion. Even some virus\experts\will misinform the cause of the virus. Let's define what we mean by virus a virus is a program that reproduces its own code by attaching itself to other executable files
一、质点的角动量定理和角动量守恒定律 (The angular momentum theorem & The law of angular momentum conservation of a mass point) 1 质点的角动量(The angular momentum of a mass point) 质量为m的质点以速度v在空间运动,某时刻相对原点O 的位矢为r,质点相对于原点的角动量