Final answer:
The average speed between 0 and 5 seconds cannot be determined without additional information on distance traveled or changes in velocity over time.
Step-by-step explanation:
To find the average speed between 0 and 5 seconds, we need to know either the total distance traveled or the initial and final velocities if the velocity is changing at a constant rate. Without this information provided in the question, we cannot determine the average speed. However, in the context given, where there was a note about reasonable average speed estimations, such as 5 meters divided by 2 seconds being 2.5 m/s, and a comparison to the speed of a brisk walk, it seems that the question expects us to use this kind of estimation or given data. Since no numerical data on distance or velocity change over time is provided here, we cannot calculate the average speed for this question.