Answer:
[tex]0.62\:\mathrm{s}[/tex]
Explanation:
Since the universal SI unit for velocity is meters/second, let's convert ft/s to m/s:
[tex]10\:\mathrm{ft/s}=3.048\:\mathrm{m/s}[/tex]
We can use the following kinematics equation to solve this question:
[tex]v_f=v_i+at[/tex]
What we know:
Solving for [tex]t[/tex]:
[tex]-3.048=3.048+(-9.8t),\\-6.096=-9.8t,\\t=\frac{-6.096}{-9.8}\approx \boxed{0.62\:\mathrm{s}}[/tex]