When you say, "Push the elephant," you want to push it in a particular way?

你刚才说,"推那头大象",你想用什么特别的方法来推吗

耶鲁公开课 - 基础物理课程节选

You should have some idea of how I'll do it.

你们应该清楚我会用什么方法解决

耶鲁公开课 - 基础物理课程节选

What do I have here? I need the variable, ANS, ANS I need x, and I need ANS times ANS, ANS times ANS. Right. Those are the three things that are involved in this computation.

因此让我先用这个方法做吧，我这里需要什么呢？我需要变量，还需要x，然后将ANS乘以ANS，对,在这个计算中涉及到了三件事情。

麻省理工公开课 - 计算机科学及编程导论课程节选

take the derivative of this, get the velocity vector and you notice his magnitude is a constant Whichever way you do it, you can then rewrite this as v square over r.

对这个式子求一次导,就能得到速度矢量,你会发现其模长是常数,不管用什么方法,加速度也可以写成 v^2 / r

耶鲁公开课 - 基础物理课程节选