Compute its instantaneous speed at time t 3s. It is thus a scalar quantity. V 81 ms.
As the interval over which an average speed is measured becomes shorter and shorter so this speed becomes closer and closer to the instantaneous speed.
The rotational speed is a slightly different term related rather to rotating objects than to objects that change their position in space. X text m xm t s t text s ts Graph of x in meters vs. S inst 55ms. Speed DistanceTime 1000 km0001 seconds 1000000 kmseconds.