The relevant equation we can use in this case would be:
v^2 = v0^2 + 2 a d
where:
v is our final velocity or landing velocity = ?
v0 is the initial velocity = 5 m/s
a is acceleration due to gravity = 9.81 m/s^2
d is distance = 25 m
So:
v^2 = 5^2 + 2 (9.81) 25
v^2 = 515.5
v = 22.70 m/s