After 3.00 s of free-fall, what is the velocity v of the stone in Figure 2.17?

Reasoning  Because of the acceleration due to gravity, the magnitude of the stone’s downward velocity increases by 9.80 m/s during each second of free-fall. The data for the stone are the same as in Example 10, and Equation 2.4 offers a direct solution for the final velocity. Since the stone is moving downward in the negative direction, the value determined for v should be negative.

Solution Using Equation 2.4, we obtain