direction Y的意思|示意

Now what I want to find,actually, V is what are these two vectors, let's call them U and V, that correspond to moving a bit in the x direction or in the y direction?

现在我实际上想知道的是，这两个向量是什么，我们称它们为，U和，两者对应的是x方向和y方向一点位移？

And I will call this direction y, as I always do perpendicular to the surface.

照惯例把垂直方向，设为y方向。

Let's first decompose this force as we did before, in the y direction.

还是照惯例,把力分解到y方向。

This is the y direction.

这是y方向。

So, the direction of the force is going to be that of x, y, z.

所以方向是。

And this is the direction, positive direction, of y.

这个方向，是y的正方向。