Well, in music the most basic symbol for the beat is the quarter note.

音乐中表示拍的最基本符号是四分音符

耶鲁公开课 - 聆听音乐课程节选

So, the two most elementary ideas you learn are what is the average velocity of an object, as then ordered by the symbol v-bar.

你们学过的两个最基本的概念是,物体的平均速度,用"v拔"表示

耶鲁公开课 - 基础物理课程节选