Answer:
48.5 m/s².
Explanation:
We can use the following kinematic equation:
[tex]\displaystyle v_f = v_i + at[/tex]
Substitute in the appropriate values and solve for acceleration a:
[tex]\displaystyle \begin{aligned} (1250\text{ m/s}) & = (280\text{ m/s}) + a(20\text{ s}) \\ \\ a & = 48.5\text{ m/s$^2$} \end{aligned}[/tex]
Therefore, the acceleration of the fighter jet was 48.5 m/s².