1. As long as the train is at a certain moment, the instantaneous speed must be 0. 2. What are the calculation formulas of instantaneous speed, average speed and speed? Because I preview it in advance, Don't be surprised to ask naive questions In addition, can you give a calculation of instantaneous velocity and average velocity?

1. As long as the train is at a certain moment, the instantaneous speed must be 0. 2. What are the calculation formulas of instantaneous speed, average speed and speed? Because I preview it in advance, Don't be surprised to ask naive questions In addition, can you give a calculation of instantaneous velocity and average velocity?

How can the instantaneous velocity be 0? The instantaneous velocity of each point is different. The definition of instantaneous velocity in senior high school physics applies the idea of limit. The moving object in a very short time (how short and how short, that is, the time tends to 0) can be regarded as uniform motion (the velocity is vector, directional, uniform motion from