(分量形式=("Fa Ⅰ=B2_R m不变时 JF(dt =m2s -mIs I,=. FOdt=mv2y-m 12=F2(dt=m2-m4 ∫ = 21 d tt I F t v v 2 1 I p p v v v = − (3)分量形式 m不变时 ∫ = 21 ( )d tt x x I F t t = mv2x −mv1x ∫ = 21 ( )d tt y y I F t t = mv2 y −mv1 y ∫ = 21 ( )d tt z z I F t t = mv 2z − mv1z