一颗子弹在枪筒里前进时所受的合力大小为 [tex=8.786x1.5]D6p1bPeeKZaEze4FJhZbgHk7EPwF5hX0IVIkus0Sbhtdl3Mq+u5dgYwf5Tc9dtQh[/tex], 子弹从枪口射出时的速率为[tex=4.357x1.357]Qvq6xvIn1a/EGro/reARjyAhZYwr5JXG6Id4knIzfRw=[/tex]。设子弹离开枪口处合力刚好为零。求:[br][/br]了弹的质量。

一颗子弹在枪筒里前进时所受的合力大小为 [tex=8.786x1.5]D6p1bPeeKZaEze4FJhZbgHk7EPwF5hX0IVIkus0Sbhtdl3Mq+u5dgYwf5Tc9dtQh[/tex], 子弹从枪口射出时的速率为[tex=4.357x1.357]Qvq6xvIn1a/EGro/reARjyAhZYwr5JXG6Id4knIzfRw=[/tex]。设子弹离开枪口处合力刚好为零。求:子弹走完枪筒全长所用的时间t 

一颗子弹在枪筒里前进时所受的合力大小为 [tex=8.786x1.5]D6p1bPeeKZaEze4FJhZbgHk7EPwF5hX0IVIkus0Sbhtdl3Mq+u5dgYwf5Tc9dtQh[/tex], 子弹从枪口射出时的速率为[tex=4.357x1.357]Qvq6xvIn1a/EGro/reARjyAhZYwr5JXG6Id4knIzfRw=[/tex]。设子弹离开枪口处合力刚好为零。求:[br][/br]子弹在枪筒中所受力的冲量l