Chapter 9 Linear Momentum and 9-2 Conservation of linear momentun(动量守恒 p202-205) In equation: FY dP net dt Let F=0 net P=constant vector 动量守恒定律 若质点系所受的合外力为零F=∑F=0 则系统的总动量守恒,即P=∑保持不变Chapter 9 Linear Momentum and Collisions 9-2 Conservation of linear momentum（动量守恒 p202-205） dt dP Fnet   In equation: = Let Fnet = 0  P = constant vector 若质点系所受的合外力为零 则系统的总动量守恒，即 保持不变 . 0 ex ex =  = i F Fi   =  i p pi   动量守恒定律