l-D Kinematics Name: Instantaneous Speed vs. Average Speed The instantaneous speed of an object is the speed that an object has at any given instant. When an object moves, it doesn't always move at a steady pace. As a result, the instantaneous speed is changing. For an automobile, the instantaneous speed is the speedometer reading. The average speed is simply the average of all the speedometer readings taken at regular intervals of time. Of course, the easier way to determine the average speed is to simply do a distance/ time ratio. 9. Consider the data at the right for the first 10 minutes of a teacher's trip along the expressway to school. Determine a. the average speed (in mi / min) for the 10 minutes of 0 0 motion. Time (min) Pos'n (mi)