my momentum and you can find the boat momentum

我的动量以及船的动量
and that's the velocity it will retain forever.

以及它将一直保持的速度
So, you need more information than

所以你需要更多已知条件
simply saying, "I jumped to the shore."

只说我落到了岸上是不够的
It depends with what velocity

还需知道
I left the boat and landed on the ground.

我离开船和着陆时的速度
If I leap really hard,

如果我猛地起跳
the boat will go really fast the opposite way.

船就会迅速向相反方向运动
Okay, that's the end of this family of center of mass problems.

好的这就是我们讨论的所有关于质心的问题
So, I'm going to another class of problems.

接下来我们来看另一类问题
This involves a rocket,

关于火箭的
and it's going to derive the rocket equation.

我们将得出火箭运动的方程