A question about the average velocity of bodies undergoing one-dimensional motion and a constant acceleration (gravity in this case). A case scenario. Suppose that initially, I throw a stone into the air at a height h. For the sake of argument, lets suppose that even though I threw the stone straight into the air, when it comes back down for the descent, it landed at a point lower than h. When t=0, the position of the stone is h and at some later time, its position is h again. The average velocity from the initial time to the time when the stone's position is h again is zero because during that time interval, the stone "replaced" all of the distance that it displaced. That I understand. Let's now examine the average velocity from t=0 to the final time when the stone is at some point lower than h. This is where I have questions. Lets make h=0, the stone's landing point is -3, the entire trip happens over 3 seconds. So then, the average velocity from [0, 3] is -1 units/second. Conceptually, what is the meaning of -1 units/second? Does the calculation disregard the "cancelled out" displacement completely?