Answer:
[tex]1.27\:\text{s}[/tex]
Explanation:
We can use the following kinematics equation to solve this problem:
[tex]v_f=v_i+at[/tex]
Solving for [tex]t[/tex]:
[tex]-24.5=-12.1+-9.8t,\\-12.4=-9.8t,\\t=\frac{-12.4}{-9.8}\approx \boxed{1.27\:\mathrm{s}}[/tex]
