[tex]\begin{gathered} Part\text{ A} \\ Total\text{ time = (2)(}2.8s\text{)} \\ Total\text{ time = 5}.6s\text{ } \\ \text{Part B} \\ v_f=gt \\ v_f=(9.81m/s^2)(2.8s) \\ v_f=27.47\text{ m/s} \\ \text{The }final\text{ landing velocity is 27.47 m/s} \end{gathered}[/tex]