* Meters per second squared (m/s²): This is the standard unit in the International System of Units (SI).

* Feet per second squared (ft/s²): This unit is commonly used in the United States.

* Kilometers per hour squared (km/h²): This unit is sometimes used for acceleration in vehicles.

It's important to note that acceleration is the rate of change of velocity over time. Therefore, the units for acceleration are derived from the units of velocity (m/s, ft/s, km/h) and time (s).