We are given the following information
Initial velocity of plane = 52 m/s
Acceleration of plane = 2.8 m/s^2
Time = 5 s
We are asked to find the final velocity of the plane.
Recall the first equation of motion given by
[tex]v_f=v_i+at[/tex]Let us substitute the given values into the above equation
[tex]\begin{gathered} v_f=v_i+at \\ v_f=52_{}+2.8\cdot5 \\ v_f=52_{}+14 \\ v_f=66\; \frac{m}{s} \end{gathered}[/tex]Therefore, the plane's velocity after 5 s is 66 m/s