Here's why:

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

* Velocity is the rate of change of position over time, measured in meters per second (m/s).

* Therefore, acceleration is measured in the change of velocity (m/s) per unit time (s), resulting in m/s².

Other units of acceleration:

While m/s² is the standard unit in the International System of Units (SI), other units are sometimes used, including:

* Feet per second squared (ft/s²): Used in the imperial system.

* Kilometers per hour squared (km/h²): Less common but sometimes encountered.

Important Note: Always be mindful of the units when working with acceleration, as different units can lead to significantly different results.