1. **State the problem:** We want to find the velocity of a rock falling freely under gravity after 4.1 seconds. 2. **Formula used:** The velocity of an object in free fall under gravity is given by $$v = g \times t$$ where $v$ is the velocity, $g$ is the acceleration due to gravity, and $t$ is the time. 3. **Given values:** - Acceleration due to gravity, $g = 9.81$ m/s² - Time, $t = 4.1$ s 4. **Calculate the velocity:** $$v = 9.81 \times 4.1 = 40.221$$ m/s 5. **Interpretation:** After 4.1 seconds, the rock will be falling at approximately 40.22 m/s downward. This velocity assumes the rock started from rest and air resistance is negligible.