Once you've got that, you can do minus 7 times a vector Just take the vector, multiply it by Pi and flip it over.

明白这点之后,你就可以计算-7乘以矢量,只需用 π 去乘以那个矢量,然后将其方向调转

耶鲁公开课 - 基础物理课程节选

Just take the derivatives and that's the velocity vector.

直接计算对时间的导数就是速度矢量

耶鲁公开课 - 基础物理课程节选

And I can find the orientation of the arrow You have the option of either working with the two components of A or with the arrow.

我也可以求得矢量的方向,你可以选择使用,A 的两个分量或者矢量图来计算

耶鲁公开课 - 基础物理课程节选