Answer;
= 3.73 seconds
Explanation;
Using the equation;
v = u + at
where v is the final velocity, u is the initial velocity and a is the acceleration due to gravity (-g) and t is the time taken.
Therefore;
v = u - gt
Thus;
v = 24.5 m/s, u = 12.1 m/s, a = -g = 9.8 m/s²
-24.5 m/s = 12.1 - 9.8 × t
36.6 = 9.8 t
t = 36.6/9.8
= 3.73 seconds