Suppose you increase your walking speed from 5m/s to 13m/s in a period of 3s what is your acceleration?

2 2/3 m/s²

Explanation:

Acceleration is a measure of change in speed over time. What it means mathematically is the difference between your ending and starting speed divided by the total time between.

Here, our starting speed is 5 m/s and our ending speed is 13 m/s, so our change in speed is 13 m/s - 5 m/s = 8 m/s, and our total time between is 3 s, so that gives us an acceleration of (8 m/s) / (3 s), which is 8/3 m/s², or 2 2/3 m/s²

(A little note: m/s² is just an abbreviation for m/s/s, or "meters per second per second," and you read it as "meters per second squared")

i'm thinking more like energy