1. Meters per second squared (m/s²): This is the most common way to express acceleration, as it directly reflects the definition of acceleration as the rate of change of velocity over time.
2. Meters per second per second (m/s/s): This is a less common but equivalent way of expressing the unit. It emphasizes that acceleration is a change in velocity (meters per second) occurring over a change in time (seconds).
Both expressions are correct and convey the same meaning.
