Answer:
To solve for the time when the football hits the ground, we need to set h = 0 and solve for t. We can do this using the quadratic equation: 0 = -3.9t² + 15.6t. Solving for t results in t = 0 or t = 4. Therefore, the football hits the ground at t = 0 seconds or 4 seconds after it is kicked. The units of measurement for time are seconds.