function of time t. A traveling object might move at different speeds and in different directions during an interval of time, but if we ask at what constant velocity the object would have to travel to achieve the same displacement over the given time interval, that is what we call the object's average velocity. We will use the notation vave[t1,t2] to indicate average velocity over the time interval from t1 to t2. For instance, vave[1,3] is the average velocity over the time interval from t=1 to t=3.