Acceleration in free fall is typically measured in meters per second squared (m/s²).

Here's why:

* Acceleration is the rate of change of velocity over time.

* Velocity is measured in meters per second (m/s).

* Therefore, acceleration is measured in meters per second per second, which is simplified to meters per second squared (m/s²).

While other units like feet per second squared (ft/s²) or centimeters per second squared (cm/s²) could be used, the standard SI unit is meters per second squared.