Hi there!
We can use the following kinematic equation to solve.

vf = final velocity (m/s)
vi = initial velocity (m/s)
a = acceleration (due to gravity, g ≈ 9.8 m/s²)
t = time (sec)
Also, we can assign UP to be positive and DOWN to be negative, so the initial velocity is positive and the acceleration due to gravity is NEGATIVE.
Plug in the values:
