Congress has often used the Commerce Clause to justify exercising legislative power over the activities of states and their citizens, leading to significant and ongoing controversy regarding the balance of power between the federal government and the states.
Instantaneous and Average Velocity. instantaneous velocity of an object at a particular time is equal to the slope of its position vs. time graph at that time. On the other hand, the average velocity between two times is equal to the slope of the line joining the two points on the position vs. time graph.
The average speed of an object in an interval of time is the distance travelled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as the duration of the time interval approaches zero. Speed has the dimensions of distance divided by time.