They would both start to slide at the same angle and the same kind of rubber.

它们都会在一样的角度开始下滑,前提轮胎是用的一种橡胶做的。

youdao

I have here that same ladder, and now what I will do is I will set the angle alpha not exactly at the critical point but a little lower, so that when I let it go, we'll all see that it will slide.

这是一个梯子，现在我要,使得角度α,不是恰等于临界点,而是略小一些，所以当我放手，我们会看到它下滑。

youdao

We know from experience that if this Angle is too small that the ladder will slide, and so I want to make the topic today "What should that Angle be so that it does not slide?"

从经验中我们，知道若这角过小，梯子就会滑下来，所以今天的主题是，“这个角度多大时，它不会滑下来。”

youdao