A watermelon is dropped from the top of a 80 m tall building. We want to find the velocity of the watermelon after it falls for 1.35 s. The watermelon has not yet hit the ground. Which kinematic formula would be most useful to solve for the target unknown?
1) v = u + at
2) v² = u² + 2as
3) s = ut + 0.5at²
4) v = u + 2as