系统总动量变化率 (pir)+ (pu ir)+ (pueui)+.(pu ruord80z fril ap 1 a +-(pu,r)+-(pun)+-(pu.)+pr Oi+ncin+lt如+n2186 t r ar r06 ar r a0 az Du =p-rOro86z Dt 柱坐标中=l,en+le+e, 06 于是 Du a a, ue a L-+ 06 Que +ugee +ue) +u Or ragaz De +. ue oue+u z +0) ar r a8 +u au u ou,+u c)e t 06 az系统总动量变化率 [ ( ) ( ) ( ) ( )] 1 1 { [ ( ) ( ) ( )] [ ]} r z r z r z ur u ur u u u ru r z t r z u u u u u ru u r u u r u u r z t r r r z t r r z Du r r z Dt + + + = + + + + + + + = 柱坐标中 , , r r r z z r e e u u e u e u e e e = + + = = − 2 ( )( ) ( ) ( ) ( ) r z r r z z r r r r r z r r r z z z z z r z z Du u u u u e u e u e Dt t r r z u u u u u u u u e t r r z r u u u u u u u u u e t r r z r u u u u u u u e t r r z = + + + + + = + + + − + + + + + + + + + 于是