1. The problem asks: What is acceleration measured in? 2. Acceleration is defined as the rate of change of velocity with respect to time. 3. The formula for acceleration is: $$a = \frac{\Delta v}{\Delta t}$$ where $\Delta v$ is the change in velocity and $\Delta t$ is the change in time. 4. Velocity is measured in meters per second ($m/s$), and time is measured in seconds ($s$). 5. Therefore, acceleration units are: $$\frac{m/s}{s} = m/s^2$$ 6. This means acceleration is measured in meters per second squared, which indicates how many meters per second the velocity changes every second.