The solution would be like this for this specific problem:
v = ?
u = 0.0 m/s
a = 9.8 m/s^2
s = 56.1 m
v^2 = (0.0 m/s)^2 + [2 * (9.8 m/s^2) * (56 m) ]
v^2 = 2 * (9.8 m/s^2) * (56 m)
v^2 = 1,097.6 m^2/s^2
v = SQRT {1,097.6 m^2/s^2 }
v = 33.1 m/s
v = u + at
(v - u) / a = t
[ (33.1 m/s) - (0.0 m/s) ] / (9.8 m/s^2) = 3.38 seconds
If the pigeon is 56.0 m below the initial position of the falcon, it will take 3.38 seconds for the falcon to reach the pigeon. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.